Nahmod Law

County of Los Angeles v. Mendez (pending): Section 1983, Proximate Cause and the Fourth Amendment

County of Los Angeles v. Mendez, No. 16-369 (argued March 22, 2017)

The Factual Background

Suppose that police officers, looking for a felony parolee-at-large with an outstanding arrest warrant, engage in a warrantless entry into a home without exigent circumstances (they should have secured a search warrant), and without knocking and announcing, in violation of the Fourth Amendment. They thereby allegedly “provoke” the plaintiff resident’s grabbing a gun (it turns out to be a BB gun), which in turn leads to their shooting and seriously injuring the plaintiff.

The Proximate Cause Questions

Does the plaintiff have a section 1983 Fourth Amendment claim against the officers for damages resulting from the use of deadly force?  The theories underlying such liability are that the warrantless entry into the home either (1) “provoked” the subsequent events or (2)  was the proximate cause of the use of the deadly force which (even if reasonable when viewed in isolation) was the reasonably foreseeable result of the warrantless entry that violated the Fourth Amendment?

These are the questions raised by Mendez v. County of Los Angeles, 815 F.3d 1178 (9th Cir. 2016), a Ninth Circuit decision that ruled for the resident, and as to which the Supreme Court has granted certiorari.

Specifically, in addition to the propriety of the Ninth Circuit’s questionable “provocation” rule, another aspect of the Question Presented is “whether, in an action brought under Section 1983, an incident giving rise to a reasonable use of force is an intervening, superseding event which breaks the chain of causation from a prior, unlawful entry in violation of the Fourth Amendment.”


There have been other section 1983 proximate cause cases before the Supreme Court, but this one is different because it raises reasonable foreseeability (and superseding cause) as the proximate cause test in a split-second decision making setting. Compare Malley v. Briggs, 475 U.S. 335 (1986), and Martinez v. California, 444 U.S. 277 (1980), both of which are discussed in sections 3:106-107 of my treatise, CIVIL RIGHTS AND CIVIL LIBERTIES LITIGATION: THE LAW OF SECTION 1983 (4th ed. 2016).

There is a critical complication in Mendez, however, that must be noted. The Ninth Circuit ruled in Mendez that the defendants did not violate clearly settled Fourth Amendment law in failing to knock and announce, even though they did violate the Fourth Amendment. That is, the defendants were protected by qualified immunity from damages liability-see Chapter 8 of my treatise–for their failure to knock and announce in violation of the Fourth Amendment, meaning that the proximate cause issue related to knock and announce may well disappear.

This is significant because it may weaken the plaintiff’s proximate cause argument. After all, isn’t the failure to knock and announce closely related in time and space to the plaintiff’s reaching for his BB gun? And isn’t this rather clearly reasonably foreseeable? On the other hand, how closely related in time and space is the defendants’ failure to obtain a search warrant to what happened later? Is this as clearly reasonably foreseeable?

The oral argument in Mendez focused on this issue, with various justices wondering about both the cause in fact and proximate cause relationship between the failure to get a search warrant and the resulting use of (constitutional) deadly force. They asked–cause in fact–whether the failure to get the search warrant made a difference in the plaintiff’s reaching for a gun (albeit a BB gun) that resulted in the use of deadly force. Several also skeptically asked–proximate cause–whether the plaintiff’s reaching for a gun was within the scope of the risk created by the failure to get a search warrant.

I suspect that a majority of the justices will rule for the defendants on this proximate cause issue. But going forward, much will depend on how the proximate cause opinion is written.

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Written by snahmod

May 10, 2017 at 10:22 am

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