CUMMINGS, Chief Judge.

Plaintiff Craig Strauss filed suit against the City of Chicago (the "City") and Chicago Police Officer John Doe under 42 U.S.C. § 1983. The district court granted the City's motion to dismiss for failure to state a claim, causing plaintiff to file a timely notice of appeal. We have jurisdiction pursuant to 28 U.S.C. § 1291 and we affirm the judgment of the lower court for the reasons stated herein.

I

For purposes of this Fed.R.Civ.P. 12(b)(6) motion, we take the factual allegations in plaintiff's complaint as true. Strauss' complaint arises out of an incident on March 14, 1983. On that date plaintiff was lawfully on the premises of 7400 North Western Avenue when Chicago Police Officer John Doe placed Strauss under arrest without probable cause, or a reasonable belief that a crime had been committed or that Strauss had himself committed a crime. Subsequent to this unlawful arrest, the unnamed police officer struck plaintiff in the face.

Strauss alleged that policies of the City proximately caused this unlawful police conduct. Specifically, he claimed that the City

a. Had a custom and practice of hiring persons such as Defendant JOHN DOE, whose prior history of brutality should have rendered them unacceptable for hire.

b. Had a custom and practice of allowing Chicago Police Officers, such as Defendant JOHN DOE, to remain cloaked with legal authority and employed as Chicago Police Officers, even though their experience on the job showed them to be brutal in nature and frequent violators of civil rights of persons in custody.

c. Had a custom and practice of allowing those in custody to be silenced by causing them to be beaten and physically abused.

d. Had a custom and practice of conducting investigations against police officers, by which said officers would be exonerated of any fault as a result of the investigative procedures employed by the police department; and which would result in the continued employment and cloak of authority upon brutal officers such as Chicago Police Officer JOHN DOE.

Strauss pled no facts to support this charge, apart from those surrounding his own unlawful arrest and physical injury. He sought compensatory damages from the City for his injuries.

II

Our analysis begins with Monell v. Department of Social Services of the City of New York, 436 U.S. 658, 690-691, 98 S.Ct. 2018, 2035-2036, 56 L.Ed.2d 611 (1978). The Supreme Court held there that municipalities could be held liable under Section 1983 for constitutional violations caused by their official policies, including unwritten customs. At the same time the Court made very clear that the language and legislative history of Section 1983 compelled the conclusion that municipalities could not be held liable solely on a theory of respondeat superior. Id. at 691, 98 S.Ct. at 2036. Proximate causation between the municipality's policy or custom and the plaintiff's injury must be present. Congress believed that to do otherwise would impose a broad, general liability raising insurmountable constitutional difficulties. Id. at 693-694, 98 S.Ct. at 2037-2038. "Instead, it is when execution of a government's policy or custom * * * by those whose edicts or acts may fairly be said to represent official policy, inflicts the injury that the government as an entity is responsible under § 1983." Id. at 694, 98 S.Ct. at 2037. This emphasis on causality and on official policy supported our holding that the "allegation of a single incident of unconstitutional conduct by a municipal employee usually does not establish a sufficient basis for suing the municipality." Powe v. City of Chicago, 664 F.2d 639, 650 (7th Cir. 1981). A successful suit requires the plaintiff to establish that he was injured, and that some municipal policy, custom or practice proximately caused the injury. Polk County v. Dodson, 454 U.S. 312, 326, 102 S.Ct. 445, 454, 70 L.Ed.2d 509 (1981); Powe, 664 F.2d at 643, 649-650; Rivera v. Farrell, 538 F. Supp. 291, 295 (N.D.Ill. 1982).

We affirm the lower court's dismissal of Strauss' complaint for failure to state a claim because he has alleged no facts to suggest that the policies of which he complains actually exist. The standard a defendant must meet to have a claim dismissed for this reason is admittedly a high one. Dismissal is improper "unless it appears beyond doubt that the plaintiff can prove no set of facts in support of his claim which would entitle him to relief." Conley v. Gibson, 355 U.S. 41, 45-46, 78 S.Ct. 99, 102, 2 L.Ed.2d 80 (1957) (footnote omitted). To further this end a court must construe pleadings liberally, and mere vagueness or lack of detail does not constitute sufficient grounds for a motion to dismiss. J. Moore and J. Lucas, 2A Moore's Federal Practice ¶ 12.08 at 2274, 2285 (1984). Still "the lack of intimation of any facts underlying the [Talley] claim," Briscoe v. LaHue, 663 F.2d 713, 723 (7th Cir. 1981) (emphasis in original), certiorari denied sub nom. Talley v. Crosson, 460 U.S. 1037, 103 S.Ct. 1426, 75 L.Ed.2d 787, justifies dismissal. Briscoe also involved a Section 1983 claim, but for conspiracy. There plaintiff Talley's only allegation of conspiracy contained legal conclusions "wholly devoid of facts," id., very similar to the situation at bar. Strauss has identified four separate "custom[s] and practice[s]," one or more of which may have caused his injury (Complaint at 2-3), but the only facts alleged relate to his arrest. Nothing in the complaint suggests that the incident was other than an isolated one unrelated to municipal policy, leading us to affirm the dismissal of the complaint, as we did in Briscoe with respect to Talley's claim.

A complaint that tracks Monell's requirement of official policy with bare allegations cannot stand when the policy identified is nothing more than acquiescence in prior misconduct. The absence of any facts at all to support plaintiff's claim renders the allegations mere legal conclusions of Section 1983 liability devoid of any well-pleaded facts. Our conclusion today does not conflict with the settled rule stated in Conley, 355 U.S. at 47, 78 S.Ct. at 103,

that the Federal Rules of Civil Procedure do not require a claimant to set out in detail the facts upon which he bases his claim. To the contrary, all the Rules require is "a short and plain statement of the claim" that will give the defendant fair notice of what the plaintiff's claim is and the grounds upon which it rests. (Footnote omitted; emphasis added.)

Plaintiff here has set out no grounds upon which his claim rests, an omission that is fatal. To allow otherwise would be tantamount to allowing suit to be filed on a respondeat superior basis. Plaintiffs could file claims whenever a police officer abused them, add Monell boilerplate allegations, and proceed to discovery in the hope of turning up some evidence to support the "claims" made. See Rodgers v. Lincoln Towing Service, Inc., 596 F. Supp. 13, 20 (N.D.Ill. 1984) (claims "based on wholly conclusory allegations of a de facto municipal policy * * *, the existence of which is to be inferred not from something the municipality did but rather from its inaction, constitute one of the most prevalent forms of abuse in section 1983 actions"); Tritsis v. Officer Owsley, No. 83 C 1264, slip op. at 4 (N.D.Ill. June 13, 1983) (no facts alleged in complaint other than those relating to the single incident involving plaintiff; court concluded that "[o]ne incident of unconstitutional conduct does not show that a city has a policy of encouraging police officers to engage in unconstitutional acts"). Cf. Smith v. Ambrogio, 456 F. Supp. 1130, 1137 (D.Conn. 1978) (court dismissed Section 1983 complaint, similar to one at bar, that was also completely lacking in any facts concerning existence of municipal policy).

The existence of a policy that caused a plaintiff's injury is an essential part of Section 1983 liability, so that some fact indicating the existence of some such policy must be pled. Without some evidence apart from the fact of employment, regardless how slight, that a policy causing plaintiff's injury might exist, the plaintiff simply cannot proceed in court against the municipality. See Sutliff, Inc. v. Donovan Co., 727 F.2d 648, 654 (7th Cir. 1984) (even under the notice pleading of the federal rules, pleader must still include either direct or inferential allegations respecting all the material elements of a claim, and bare legal conclusions attached to the narrated facts will not suffice).

Strauss did attempt to establish the minimal facts required by including statistical summaries from the Office of Professional Standards regarding complaints filed with the police department (memo in opposition to motion to dismiss). In Powe, supra, we stated that "the allegation of a pattern of conduct or a series of acts violative of constitutional rights will in many cases raise an inference of municipal policy." Powe, 664 F.2d at 651. While the type of information plaintiff provided us could furnish the necessary foundation to allege a "pattern of conduct or a series of acts," the generalized summaries to which Strauss points do not meet even the low pleading threshold established in the federal courts. Plaintiff suggests that the police department's sustaining only six to seven percent of all registered complaints filed for 1977, 1978 and 1979 "must give rise to a reasonable man's suspicions that defendant Chicago's methods of review are weighted to discourage positive findings" (memo in opposition to motion to dismiss at 6). This reasoning is specious, for the number of complaints filed, without more, indicates nothing. People may file a complaint for many reasons, or for no reason at all. That they filed complaints does not indicate that the policies that Strauss alleges exist do in fact exist and did contribute to his injury.

At the very least Strauss "would need to identify as well what it was that made those prior arrests * * * illegal and to show that a similar illegality was involved in his case." Ekergren v. City of Chicago 538 F. Supp. 770, 773 (N.D.Ill. 1982). Judge Getzendanner in Ekergren distinguished the situation where "[g]eneral, unspecific allegations of frequent 'illegal arrests' * * * fail to establish any pattern" from her earlier decision in Spriggs v. City of Chicago, 523 F. Supp. 138 (N.D.Ill. 1981), in which "this court found a sufficient pattern in allegations that the police regularly use violence in dealing with black suspects." Ekergren, 538 F. Supp. at 773. Strauss' data similarly represent nothing more than generalized allegations bearing no relation to his injury.

We do not mean to imply that a plaintiff must plead in greater detail, but merely that the plaintiff must plead some fact or facts tending to support his allegation that a municipal policy exists that could have caused his injury. Identifying such facts is of course more difficult when the policy through which plaintiff is aggrieved is one of acquiescence by the City in prior misconduct, thus encouraging the misconduct to continue, than when the policy is an affirmative one through which the City has acted to harm the plaintiff. Murray v. City of Chicago, 634 F.2d 365 (7th Cir. 1980), certiorari granted sub nom. Finley v. Murray, 454 U.S. 962, 102 S.Ct. 501, 70 L.Ed.2d 377, certiorari dismissed, 456 U.S. 604, 102 S.Ct. 2226, 72 L.Ed.2d 366, illustrates the difference. In Murray plaintiff was arrested, taken to police headquarters, forced to submit to strip searches, and imprisoned for several hours on an invalid warrant that had been quashed over three months earlier. The warrant recall had never been transmitted properly from the clerk's office to the police department. We reversed the district court's motion to dismiss, explaining that "[s]omeone is surely at fault for failing to establish or execute appropriate procedures for preventing such serious malfunctionings in the administration of justice." Id. at 366. The omission involved not acquiescence in prior misconduct but action or inaction on the part of the City itself that directly caused plaintiff's wrong. The omission was sufficiently egregious that plaintiff's injury alone suggested an established policy. Since it was possible that the plaintiff might be able to establish the existence of a policy, custom, or practice, the City was not dismissed at that early stage in the lawsuit. Id. at 367.

In the case at bar, plaintiff has alleged something less than the failure to establish or execute appropriate procedures; he has alleged a policy of knowingly acquiescing in an individual police officer's brutality. This claim requires some fact on which plaintiff's opinion is based, a fact not included in his pleadings. We are sympathetic to Judge Marshall's concerns expressed in Means v. City of Chicago, 535 F. Supp. 455 (N.D.Ill. 1982), that plaintiffs will lack the information necessary to meet even the minimum pleading requirements we set out here until they are allowed discovery and that dismissing such claims prematurely could permit constitutional violations to go unremedied. If any city indeed has a custom of institutionalized brutality, then those injured are entitled to relief under Section 1983. Judge Marshall eloquently stated:

We are at a loss as to how any plaintiff, including a civil rights plaintiff, is supposed to allege with specificity prior to discovery acts to which he or she personally was not exposed, but which provide evidence necessary to sustain the plaintiff's claim, i.e., that there was an official policy or a de facto custom which violated the Constitution.

Id. at 460.

But the complaint before us illustrates the possibilities in drafting that Judge Marshall's approach leaves open to a creative lawyer. All counsel would need to do would be to concoct some explanation of plaintiff's injury that implicated the municipality — for example, a custom and practice of hiring as police officers those with a history of brutality — and the doors of the federal courtroom would swing open. Congress did not intend for Section 1983 liability to be so wide; mere employment of a tortfeasor is insufficient to impose liability on a municipality. Instead a cause of action will lie only for those injuries caused by faults "systemic in nature," Powe, 664 F.2d at 651. Because a municipality can be held liable only for its regular procedures, not for the isolated independent tort of an individual employee, some fact indicating such procedures must appear in the complaint.

Once the district court dismissed plaintiff's complaint for failure to state a claim, Strauss could either have sought the right to amend his complaint pursuant to Fed.R.Civ.P. 59(e) or 60(b) or stood on his complaint and appealed. J. Moore, 3 Moore's Federal Practice ¶ 15.07[2] at 15-51 (1984). His having elected the latter alternative after having had the opportunity to amend justifies the affirmance of the district court's dismissal. Plaintiff now argues that he should be permitted at least to amend the complaint to name the defendant John Doe and pursue his claims against him. Plaintiff has already had full opportunity to seek amendment, but has failed to do so. Moreover, John Doe was never served with summons and a copy of the complaint, so that the district court lacked jurisdiction over him. In this situation, dismissal of both parties was proper. The district court's judgment is affirmed.