(Reversing and remanding 118 Wis.2d 824, 349 N.W.2d 110 (Ct.App. 1984).)

HEFFERNAN, CHIEF JUSTICE.

This is a review of a decision of the court of appeals which affirmed the conviction of Johrie Dyess for homicide by the negligent use of a motor vehicle.

We reverse the court of appeals, because the jury instructions violated sec. 903.03(3), Stats., in that the jury was told that it was required to find the defendant had committed an element of the crime, i.e., that he was negligent, if there was evidence from which the jury could conclude that the defendant was exceeding the speed limit at the time the accident occurred. We conclude that the error was prejudicial. We reverse and remand for a new trial.

The undisputed facts underlying the prosecution are these. On May 31, 1982, Dyess, the twenty-three-year-old defendant driver, collided with a vehicle driven by Jack Rizzo at an intersection in the city of Racine. At the time, Dyess was proceeding west, Rizzo north. Dyess had the directional right-of-way and, in addition, he was proceeding on what was at that point an arterial highway. Rizzo's entrance into the intersection was subject to a stop sign controlling traffic intending to cross 14th street, the arterial on which Dyess was proceeding. There were no traffic control signs on 14th street which required Dyess to stop. The posted and authorized speed limit for the westbound Dyess was 30 miles per hour. The speed limit for the northbound Rizzo was 25 miles per hour.

Disputed are the questions of whether Rizzo ever made the required stop before entering the intersection and whether Dyess was exceeding the 30-mile-per-hour speed limit.

The Dyess vehicle struck the right rear quarter of the Rizzo car, causing Eve King, a passenger in the Rizzo car, to be thrown out of the vehicle. Initial investigation at the scene did not indicate serious injuries. However, internal bleeding resulting from the accident subsequently caused the death of King.

Dyess was charged with homicide by negligent use of a vehicle.

Two Racine Police Department traffic officers testified that, based on the damage to the vehicles, the speed of the Dyess car was a contributing factor in the accident. One officer testified that, based on the damage to the vehicles and their positions on the roadway, the Dyess car was proceeding at a speed in excess of the posted limit of 30 miles per hour. Neither officer observed the speed of either vehicle or the conduct of the respective drivers prior to the collision.

Two additional witnesses for the state, Edwin and Judith Kossow, testified that, about two blocks from the site of the accident, while they were at a stop light, they were passed by a vehicle they stated was Dyess' at a speed originally testified to as 40 miles per hour. Edwin Kossow acknowledged that his estimate could be inaccurate by five miles per hour and stated it was possible, but not likely, that he might be in error by as much as 10 miles per hour. He acknowledged that he could not estimate the speed of the Dyess vehicle at the point of the collision two blocks away.

Judith Kossow gave similar testimony, stating that she believed the Dyess vehicle was going 40 miles per hour. While she acknowledged some fallibility in her estimate of speed, she did not think the Dyess car was going as slowly as 30 miles per hour.

Another state witness, who originally testified that Dyess was proceeding at a speed of 50 miles per hour or more, acknowledged on cross-examination that his estimate of speed was based on the post-collision damage and not upon the observation of the vehicles prior to the crash.

None of the state's witnesses professed to be expert in the field of accident reconstruction, and none of them had any training in the science of determining speed from post-crash-damage evidence.

Dyess presented three witnesses whose testimony, if believed, would have supported a finding that his speed was lawful.

A member of Northwestern University's Traffic Institute testified for Dyess as an expert that, based upon the damage, the speed at impact of the Dyess car was 21 or 22 miles per hour, subject to a possible error of less than two miles per hour.

The passenger in the Dyess car, Gerald Simpson, stated that the speed of his host's vehicle as it entered the intersection was 20-25 miles per hour. He made his estimate of speed on his experience as a driver of automobiles. He denied that Dyess had run a red light two blocks back and stated the light had flashed yellow just as they entered that intersection.

Dyess testified on his own behalf and stated that he had not been exceeding the 30-mile-per-hour limit at any time just prior to the accident. He stated that he knew this because he had checked his speedometer.

Moreover, there was evidence that Rizzo had failed to stop, as required, before entering the intersection. The original accident report of Officer Michael R. Miller stated that a factor in causing the collision was Rizzo's failure to yield the right-of-way. Additionally, Cecilia Totten, who was proceeding south on Park street, approached the intersection at approximately the time of the collision. She testified that she was "very sure" that Rizzo had not made the required stop before entering the intersection.

Rizzo was cited under a municipal ordinance for failure to yield the right-of-way. This municipal citation was dismissed after the criminal charge was brought against Dyess. The circuit judge, citing Barren v. State, 55 Wis.2d 460, 463, 198 N.W.2d 345 (1972), refused to allow the ordinance violation to be used for impeachment purposes. Accordingly, the jury was not informed that there ever was a municipal action brought against Rizzo.

At the time of the jury instruction conference, the trial judge was persuaded, over the objection of defense counsel, to include the substance of Civil Jury Instruction No. 1290 in the instructions to the jury.

This civil jury instruction found expression in the jury instruction in the following form:

"Under Wisconsin law, regulating speed of motor vehicles, it is provided that no person shall drive a vehicle at a speed greater than is reasonable and prudent under the conditions and having regard for the actual and potential hazards then existing, and that the driver shall exercise ordinary care to so regulate his rate of speed as may be necessary to avoid colliding with any object, person, vehicle or other conveyance on or entering the highway in compliance with legal requirements and using due care.

"The safety statute in the motor vehicle code provides that, no person shall drive a vehicle at a speed in excess, and on 14th Street in particular, of 30 miles per hour. Any speed in excess of that limit would be negligent speed regardless of other conditions. It is for you to determine whether Johrie Dyess's speed was over said limit and, if under, whether it was, nevertheless, a negligent speed under the conditions and circumstances then present and under the rules of law given to you in these instructions." (Emphasis supplied.)

The trial court went on to point out, however, that more than a finding of negligence was required to sustain a criminal conviction under sec. 940.08, Stats.:

"But the negligence which constitutes a high degree of negligence and which is requisite for conviction of homicide by negligent use of a vehicle is conduct that not only creates an unreasonable risk of bodily harm to another but also involves a high degree of probability that substantial bodily harm will result to such other person.

"In other words, the danger of injury which characterizes ordinary negligence is magnified to a high degree."

The jury returned a verdict of guilty. Because of Dyess' prior good record, no incarceration was imposed. Rather, Dyess was directed to perform a substantial amount of community service work.

Motion for new trial was brought on several grounds, all of which were denied.

On appeal to the court of appeals, Dyess argued that the trial court had improperly permitted testimony of speed based on the opinion of non-experts' evaluation of post-collision damage, and also argued that the jury instructions were constitutionally and statutorily invalid, because they created a conclusive presumption of negligence. Additionally, it was argued that the instructions were invalid because they misdefined reasonable doubt.

The decision of the court of appeals affirmed the trial court. The opinion was largely devoted to the evidentiary questions, all of which were resolved against Dyess.

The argument that the jury instructions improperly and impermissibly directed the jury to find an elemental fact necessary to prove criminal conduct was disposed of in a few words:

"Dyess contends that speeding is the 'basic fact' and negligence is the elemental fact to be presumed.

"Dyess' argument might be successful if a finding of guilt under sec. 940.08, Stats., rested on a mere finding of negligence. A jury however, cannot stop its consideration at that point. A jury must find not only negligence but also a 'high degree of negligence' as defined by the trial court. Negligence is not an elemental fact of the offense charged. A high degree of negligence is the elemental fact, and the instruction does not create a presumption as to a high degree of negligence.[1]

The same rationale defeats Dyess' Argument premised on sec. 903.03(3), Stats. That statute requires special additional instruction only if the presumed fact is an element of the offense." Slip opinion, pages 7-9.

Dyess petitioned this court for review. Upon acceptance of the petition, we stated that we would not review whether the admission of non-expert police testimony as to speed was harmless but we would review whether the standards of sec. 903.03(3), Stats., and the constitution were adhered to in instructing the jury.

In the event we conclude that the statutory standards of sec. 903.03(3), Stats., were not adhered to, we need not determine whether or not the instructions were constitutionally impermissible under the strictures of Sandstrom v. Montana, 442 U.S. 510 (1979). This court has frequently concluded that it need not address a claim of constitutional error if the claim can be resolved on statutory or common law grounds. Labor Farm Party v. Elections Board, 117 Wis.2d 351, 354, 344 N.W.2d 177 (1984); Kollasch v. Adamany, 104 Wis.2d 552, 561, 313 N.W.2d 47 (1981).

We therefore consider the correctness of the questioned jury instructions first on the statutory ground. Do the rules of evidence, sec. 903.03(3), Stats., adopted by this court prohibit an instruction which requires a jury to find a presumed fact necessary to support a conviction because the basic facts appear in the evidence from which the jury could infer the presumed fact. We conclude that our rules specifically give no approval to the form of instruction used and that the instruction here was tantamount to directing the jury to bring in a finding that was essential to the determination of guilt. As sec. 903.03(2) points out, "The judge is not authorized to direct the jury to find a presumed fact against the accused." Because this erroneous partial direction of the verdict had the effect of denying the defendant a substantial right — the right to have an undirected jury determination on the basic question of negligence — the error was not harmless under the provisions of sec. 805.18 and in light of the evidentiary facts revealed in the record as a whole. Because we conclude that the instruction constituted prejudicial error under sec. 903.03 (3), Stats., we need not reach the constitutional issue of the validity of the instruction under Sandstrom v. Montana, 442 U.S. 510 (1979).

Dyess specifically contends that the instruction violated sec. 903.03(3), Stats., which requires that:

"Whenever the existence of a presumed fact against the accused is submitted to the jury, the judge shall give an instruction that the law declares that the jury may regard the basic facts as sufficient evidence of the presumed fact but does not require it to do so."

The state argues that Dyess waived his objection on sec. 903.03, Stats., grounds by his failure to specifically refer to that rule when objecting to the instructions at trial. It is clear, however, that the defendant at trial did specifically object to the use of Civil Jury Instruction No. 1290, speed in excess of posted limits as being negligent. That objection went to the very heart of the rationale by which directions to the jury to find presumed facts against a defendant are forbidden in criminal cases although they may be permissible in civil cases. The substance of the objection was clearly stated.

Moreover, the strictures of sec. 903.03(3), Stats., go to the authority of the judge. They deny the judge the prerogative in a criminal case to place certain limitations upon a criminal defendant's right to a jury finding under the Wisconsin law. If error there be in this case, it is within the discretion of this court to determine whether the judge acted unlawfully and in excess of his authority in light of sec. 903.03, irrespective of whether there was an objection based on a specific statute or rule. This court exercised its discretion when, in its order granting review, it directed an inquiry into the effect of sec. 903.03(3). The court of appeals did not dispose of the sec. 903.03 position on the state's argued waiver grounds. Instead, it perfunctorily addressed defendant's argument in footnote 1 of its per curiam opinion by saying that the fact directed to be found, negligence, was not an element of sec. 940.08.

We are satisfied that the question of whether the instruction satisfied the evidentiary rule regarding presumptions in criminal cases is properly before the court. Moreover, even were there a meritorious waiver argument — and there is none in this case — the contemporaneous-objection rule is not as inflexible as the state insists. In the absence of a defendant's "right" to raise a question not contemporaneously raised by objection at trial, this court, even prior to the broad discretionary grant of power to consider issues specifically conferred by the 1977 constitutional revision, had the option of considering issues if it appeared to the court to be in the interests of good judicial administration to do so. See, State v. Cheers, 102 Wis.2d 367, 378 n. 7, 306 N.W.2d 676 (1981).

The state also argues that sec. 903.03(3), Stats., is simply not applicable to the issue which the jury was directed to find. The state does not argue that the instruction did not tell the jury that, if it did find from the evidence that Dyess was speeding, then it must in further answering the questions presume or find that Dyess was negligent. The state argues this directed finding is not a factual conclusion but a legal one. Hence, the state argues, it was not error to direct a "finding" or "conclusion" on this legal question. The state points out that the constraints of sec. 903.03(3) refer only to the "existence of a presumed fact." (Emphasis supplied.) However, the very language of sec. 903.03(1) refutes this argument, for it sets forth that the statute, sec. 903.03 as a whole, governs presumptions "recognized at common law." Hence, even were we to accept the semantics of the state's argument that it is a common law presumption in civil law that one who is speeding is negligent, in the criminal law, under sec. 903.03(3), the basic facts create at best only an inference from which a presumed fact may be arrived at in the jury's discretion, but the presumption cannot be compelled at the judge's direction.

No one in the instant case finds fault with Civil Jury Instruction No. 1290 as used in civil cases, but the authority to direct a jury in a criminal case that speed in excess of the posted limit, regardless of other conditions, is negligence, is specifically prohibited by sec. 903.03(3), Stats.

It is clear from the Judicial Council's notes to sec. 903.03, 59 Wis.2d R57 (1973), that the restrictions in that rule apply to all presumptions sought to be used in criminal cases. No exceptions to the rule have been sanctioned on the basis that the matter to be presumed is legal rather than factual in nature.

The state also argues that sec. 903.03(3), Stats., is not applicable, because a permissive inference instruction is required only when "the existence of a presumed fact against the accused is submitted to the jury." The state would attempt to eviscerate the rule by saying that, because the judge decided the negligence question as a matter of law — i.e., if the jury found Dyess was travelling in excess of 30 miles per hour, he was negligent — the negligence question was never submitted to the jury. Hence, the state argued that the provisions of sec. 903.03(3) are irrelevant.

This analysis of the statute fails to consider the difference between a basic fact and a presumed fact. The statute applies when the jury is presented with basic facts, which it may or may not accept, and is then asked to use them as an inferential basis for determining a presumed fact. Here, the basic facts — which were disputed — were the evidentiary tidbits regarding the speed of the Dyess car. The presumed fact which could have been arrived at by a process of jury inference was negligence. The state evinces confusion by assuming that the presumed fact was whether the speeding of Dyess' car was negligent conduct. This rationale which telescopes and intermingles the basic facts with the fact sought to be presumed, thwarts any articulable analysis of the statute in relation to the situation here.

The state also contends that the statute only applies when the judge instructs in terms of a permissive inference, but when the judge phrases his directions in the terms used here, as a conclusive presumption — "speeding is negligent conduct" — no statutory prohibition is violated. To so conclude would, however, make nonsense of the rule, which by its terms is intended to govern the use of any theories of common or statutory law whereby certain facts may be presumptive proof of other facts in criminal prosecutions.

This latter argument of the state, to give it the benefit of some semblance of rationality, may be but a variant of the argument earlier addressed — that negligence is not a presumed fact at all because it is a legal conclusion and, therefore, beyond the reach of the rule.

The basic argument of the state before the court of appeals — and it was upon this that the court of appeals relied — was that sec. 903.03(3), Stats., places restrictions only upon the presumptive determination of the "elements" of a crime and not upon other facts.

The court of appeals found no violation, because, under sec. 940.08, Stats., "[a] high degree of negligence is the elemental fact, and the instruction does not create a presumption as to a high degree of negligence." (Emphasis supplied.) Slip opinion at page 8.

The court of appeals, as well as the trial court, concluded that negligence was not an element of the crime and it is only "elements" that may not be determined by judge-directed presumptions.

If, however, sec. 903.03, Stats., were applicable only to elements of a crime and negligence is not an element of sec. 940.08, then the statute would be irrelevant. To so contend is to disregard the very words of the statute. Sec. 903.03(1), in describing the scope of the rule, refers to "facts" that are prima facie evidence of other "facts." Sec. 903.03(3) refers to "presumed facts." Nowhere is there any reference to "elements" of a crime which would lead a reasonable reader to conclude that directed presumptions are permissible if the matter to be presumed is not an element of the crime. Had the intent been to limit the application of the rule to "elements," the drafters of the rule would have so specified. Moreover, the scriveners of the state rule in their report include the comments of the Federal Advisory Committee on the analogous rule. The Federal Committee stated that the statute addresses presumptions as to any fact before the jury whether or not the fact establishes guilt or is an element of the offense. 59 Wis.2d at R64.

Sec. 903.03(3), Stats., makes no distinction between presumptions as to elements of a crime and presumptions as to facts with a "lesser effect" with respect to the requirement that the jury be instructed only as to the permissive inference that may be drawn from basic facts believed beyond a reasonable doubt.

The trial judge, had he followed the directions of sec. 903.03(3), Stats., would have informed the jury that, if it found as a matter of fact that Dyess was exceeding the posted speed limit of 30 miles per hour, it could regard that fact as sufficient evidence of negligence to make that finding but it was not required to do so.

Here the trial judge told the jury that, "Any speed in excess of that [30 miles per hour] limit would be negligent speed regardless of other conditions." He then went on to tell the jury that, were they to find that the speed was under 30 miles per hour, they could nevertheless determine whether the speed was negligent. The jury was mandatorily directed to find negligence if speed in excess of 30 miles per hour was proved. Discretion to permissibly draw an inference from the facts was vested in the jurors only if they found the speed to be less than that posted.

Here the judge required the jury to find the presumed fact on the evidence of the basic facts. This was in violation of the rule:

". . . the judge shall give an instruction that the law declares that the jury may regard the basic facts as sufficient evidence of the presumed fact but does not require it to do so." (Emphasis supplied.) Sec. 903.03 (3), Stats.

No language in the judge's charge permitted the jury to conclude that it was permitted but not required to use the evidence of speeding as proof of negligence.

The instruction given was violative of sec. 903.03(3), Stats. This finding of error requires us to consider whether the error was harmless.

We conclude that the error was not harmless and the judgment must be reversed.

This court for years has been struggling with methodology to rationalize upholding a conviction despite the acknowledgment that error has been committed. Certainly, many errors in the course of trial are of a trivial nature and affect the final result not one whir. Hence, it is reasonable, in accordance with public policy and judicial economy, to affirm convictions unless it is apparent that the procedure has been unfair, rights have been subverted, or an injustice has been done. Most errors are truly harmless. Nevertheless, the great virtue of our legal system — at least its great objective — is that only the guilty be convicted and even the guilty be convicted only by due process of law after guilt has been demonstrated beyond a reasonable doubt. Hence, when error is committed, a court should be sure that the error did not affect the result or had only a slight effect. While our numerous efforts to adopt an ad hoc "harmless error" methodology cannot be said to have resulted in a course of injustice, they do not reveal a coherent articulable philosophy consistent with the elementary principles stated above. When it is clear that error has been committed, we should be sure that the error did not work an injustice. The only reasonable test to assure this result is to hold that, where error is present, the reviewing court must set aside the verdict unless it is sure that the error did not influence the jury or had such slight effect as to be de minimus. This test has been adopted in State v. Poh, 116 Wis.2d 510, 529, 343 N.W.2d 108 (1984); State v. Burton, 112 Wis.2d 560, 571, 334 N.W.2d 263 (1983); State v. Billings, 110 Wis.2d 661, 667, 329 N.W.2d 192 (1983).

While these cases have involved constitutional error, as Kelly v. State, 75 Wis.2d 303, 317 n. 3, and 321 (concurring opinion), 249 N.W.2d 800 (1977), points out, the test was originally formulated by the United States Supreme Court in Kotteakos v. United States, 328 U.S. 750 (1946), where the error was of non-constitutional proportions. The test of constitutional error of Poh, Burton, and Billings was based on the rationale of the concurring opinion of Kelly v. State, 75 Wis.2d at 321, which, in turn, rested on the rationale of Kotteakos v. United States, supra, and United States v. Agurs, 427 U.S. 97 (1976). The majority in Kelly acknowledged that the test of the majority opinion and the test of the concurring opinion in that case would have yielded the same result irrespective of how the harmless error rule was explained or justified. There seems to be no special virtue in having different harmless error tests for constitutional error and non-constitutional error. Moreover, this court has more and more resorted to the Agurs-Kotteakos-Kelly concurrence methodology as a test of harmless error in cases involving non-constitutional, as well as constitutional, error. State v. Cartagena, 99 Wis.2d 657, 671, 299 N.W.2d 872 (1981); Barrera v. State, 99 Wis.2d 269, 295, 298 N.W.2d 820 (1980); Pohl v. State, 96 Wis.2d 290, 312, 291 N.W.2d 554 (1980); and Novitzke v. State, 92 Wis.2d 302, 308, 284 N.W.2d 904 (1979), were all non-constitutional error cases in which this court concluded that the proper test was whether there was a reasonable possibility that the error contributed to the conviction. As this formulation was stated by Justice Callow in Novitzke, supra:

". . . the harmless error test would require reviewing courts to set aside the verdict and judgment unless sure that the error did not influence the jury or had but only slight effect. Kelly v. State, 75 Wis.2d 303, 317 n. 3, 249 N.W.2d 800 (1977)."

This court has often noted that there is little practical difference between the formulations of harmless error which the court has used from time to time. Often, we have concluded that the determination of whether the trial error was harmless is unaffected by the particular formulation of the harmless error test used. Cartagena, 99 Wis.2d 657, 671; Pohl, 96 Wis.2d 290, 311-12; Novitzke, 92 Wis.2d 302, 308; Kelly, 75 Wis.2d 313, 317 n. 3.

We conclude that, in view of the gradual merger of this court's collective thinking in respect to harmless versus prejudicial error, whether of omission or commission, whether of constitutional proportions or not, the test should be whether there is a reasonable possibility that the error contributed to the conviction. If it did, reversal and a new trial must result. The burden of proving no prejudice is on the beneficiary of the error, here the state. Billings, 110 Wis.2d at 667. The state's burden, then, is to establish that there is no reasonable possibility that the error contributed to the conviction.

In arriving at this formulation as the standard for assessing prejudice, we take guidance from the recent United States Supreme Court decision in Strickland v. Washington, ___ U.S. ___, 104 S. Ct. 2052 (1984). In Strickland, the Court stated the test of prejudice which must be applied to determine whether reversal is required in cases of defective performance by counsel. The conviction must be reversed, under Strickland, if:

". . . there is a reasonable probability that, but for . . . [the] errors, the result of the proceeding would have been different. A reasonable probability is a probability sufficient to undermine confidence in the outcome.

. . . [T]he question is whether there is a reasonable probability that, absent the errors, the factfinder would have had a reasonable doubt respecting guilt. . . . Taking the [findings unaffected by error] as a given, and taking due account of the effect of the errors on the remaining findings, a court making the prejudice inquiry must ask if . . . the decision reached would reasonably likely have been different absent the errors." ___ U.S. ___, 104 S.Ct. at 2068-69.

Although the Court uses the words, "reasonable probability" of a different outcome, in contrast to our use of "reasonable possibility," it is clear from the Strickland opinion that the Supreme Court's test is substantively the same as ours. The Supreme Court uses the word, "probability," in the sense of likelihood. ___ U.S. ___, 104 S.Ct. at 2069. It explains that for a different outcome to be "reasonably probable" it need not be "more likely than not" ( id. at 2068); a reasonable probability of a different outcome is one that raises a reasonable doubt about guilt, a "probability sufficient to undermine confidence in the outcome" of the proceeding. Id. at 2068-69.

This formulation of the test for prejudice is not binding on this court in this case because the error we address is neither one of constitutional statute nor one of deficient performance by counsel. Nevertheless, we find the Strickland formulation instructive.

The Strickland analysis confirms our recognition in recent cases that there are few meaningful distinctions among the various formulations of the test for prejudice. See, 104 S.Ct. at 2068. We conclude that the test of prejudice as formulated in Strickland subsumes the various statements of the harmless error test that this court has used over the years.

This formulation, with its focus on whether the error "undermine[s] confidence in the outcome" ( 104 S.Ct. at 2068), is sufficiently sensitive and flexible to apply to a wide range of trial errors. Where the error affects rights of constitutional dimension or where the verdict is only weakly supported by the record, the reviewing court's confidence in the reliability of the proceeding may be undermined more easily than where the error was peripheral or the verdict strongly supported by evidence untainted by error. See, 104 S.Ct. at 2069; id. at 2073 (Brennan, J., concurring in part and dissenting in part); id. at 2080 n. 17 (Marshall, J., dissenting).

In the instant case, the erroneous instruction which directed the jury to find negligence on the basis of speed without having the permissive option of rejecting the finding of negligence simply had the effect of wiping out all other evidence on the subject of negligence. Here the jury was told if Dyess was proceeding at over 30 miles per hour, its job in determining whether or not there was negligence was at an end. The only question was how high the degree of negligence — and in this case death did result. Hence, the instruction pretty much removed any jury scrutiny of negligence from the equation of guilt. Under the instructions, there was no intimation that the jury had to look to any other factors upon which negligence could be predicated.

Although management and control and lookout were mentioned, in effect the jury was told it could forget about those factors if it found speed — and if it found speed, negligence ipso facto follows. Thus, the faulty instruction completely permeated and polluted any jury scrutiny of the evidence. There was no other evidence that needed to be looked at. It cannot be said in the scenario of this trial that there was any unpolluted and untainted evidence of negligence.

In the present case, the probability to be weighed is whether the defendant would have been acquitted. Under the facts, the probability of acquittal was substantial in the absence of the error; and in view of the test that guilt must be proved beyond a reasonable doubt, it seems rather apparent that, absent the error, the prospect of conviction would have been substantially less. As pointed out above, the instruction tainted all evidence and could have led a reasonable jury to conclude that no independent evaluation of negligence was required — that proof of speed was sufficient to mandate a conclusion of negligence — and here, where death did ensue, the step to the question of a high degree of negligence was a short step indeed. Moreover, the evidence was close and disputed. While the jury can believe one witness and disbelieve a hundred others, here the evidence of every witness for the state on the question of speeding was equivocal or shown to rest on barely supportable premises. The judge recognized that the question for the jury was close indeed. In such circumstances, it appears likely that, to instruct the jury to give undue — indeed unlawful — mandatory effect to circumstantial evidence substantially skewed the jury's determination to a verdict of guilt. Additionally, Dyess' defense was essentially a "no negligence" defense. To err in that particular — in respect to the defense upon which Dyess based his case — is almost ipso facto prejudicial.

We conclude that, in a case such as this, where the judge erred in the application of the rules of evidence to the case and that error was in respect to a crucial and controlling feature of the crime, the judgment should be reversed unless we can be sure that the error did not contribute to the guilty verdict. Here, looking to the totality of the record, it is apparent that such assurance cannot be reached with any degree of confidence. Hence, in this criminal case the conviction must be reversed.

We recognize that the test of prejudice that we apply here is not completely satisfactory, for it is difficult for this court to assess the likelihood of the jury acting one way or another, had it been properly instructed, when as here the case was a close one. It is apparent that for this court by hindsight to state that the result would have been more favorable to the defendant were the trial conducted under optimum circumstances is in itself a usurpation of the function of the jury, but no more so than to hold that, had the error not been committed, the jury would have reached the same result. At least the former alternative, which results in the granting of a new trial, leaves it to a jury to try again under more propitious circumstances.

Our position is given support by the language of sec. 805.18, Stats., supra. While sec. 805.18(2) is a part of the Code of Civil Procedure and on its face applies only to civil cases, this court has applied its rule to criminal cases, because sec. 972.11(1) makes the rules of evidence and civil procedure applicable to those cases as well. While a judgment will not be reversed under sec. 805.18 (2) unless the error affects a substantial right of a defendant, in the instant case it is exactly such a substantial right that was effectively curtailed when the trial judge directed a verdict on the question of negligence rather than permitting the defendant the right to have the jury deliberate on the inference to be drawn from the basic facts.

As the comments of the Judicial Council to sec. 903 of the Rules of Evidence indicate, the principal purpose of the section concerned with presumptions in criminal cases is to assure that judges and lawyers, by the use of desirable presumptions and prima facie evidence, not inadvertently direct verdicts of guilty in criminal cases. To do so would be to deprive a criminal defendant of the presumptions of innocence that are inherent in the criminal process. The adherence to the evidentiary rules set forth in sec. 903.03, Stats., will tend to obviate running afoul of the constitutional restrictions against mandatory presumptions which may result in the denial of a jury trial or a denial of constitutional due process — issues which we do not, and need not, address in this opinion.

It is apparent that a reviewing court cannot say that the loss of a jury right on a crucial issue guaranteed by the rules is of so little consequence as to be insubstantial. Sec. 903.03(3) guarantees to criminal defendants that all presumptions used will have a permissive effect only — that only the jury can find the presumed fact upon the inferences from basic facts which themselves must be proved to the jury beyond a reasonable doubt. This court cannot ignore its own rules and conclude that the deprivation of a substantial procedural and statutory right caused by faulty jury instructions did not, to a degree of reasonable possibility, contribute to the verdict of guilty. Accordingly, the decision of the court of appeals is reversed and the cause is remanded to the circuit court for a new trial.

By the Court. — Decision reversed, and cause remanded to the circuit court for a new trial.