Causation — Connecting Each Defendant to Your Harm
Every defendant in your § 1983 case must be personally connected to the specific constitutional violation — naming someone isn't enough.
Causation is the #1 killer of pro se § 1983 cases at the motion to dismiss stage. The rule is straightforward: you must show that each defendant personally caused or directly contributed to the violation of your constitutional rights. Naming someone in the caption isn’t enough. Saying they “should have known” usually isn’t enough. You need to connect each person to what actually happened to you.
The Rule
Under § 1983, liability is personal. Each defendant must have been personally involved in the constitutional violation. This means you need to show what that specific person did (or deliberately failed to do) that caused your injury.
This is different from many areas of law where an employer is automatically liable for what employees do. In § 1983, respondeat superior doesn’t apply. The police department can’t be liable just because it employs the officer who hurt you. The chief can’t be liable just because they’re in charge.
What Good Causation Looks Like
Direct involvement:
“Officer Smith tackled Plaintiff to the ground, placed his knee on Plaintiff’s back, and handcuffed Plaintiff while Plaintiff was face-down and not resisting.”
This connects a specific officer to specific conduct that caused specific harm.
Failure to intervene:
“Officer Jones stood within arm’s reach while Officer Smith struck Plaintiff repeatedly. Officer Jones made no effort to stop the assault despite having both the opportunity and the duty to intervene.”
This connects Jones to the harm through failure to intervene — a recognized basis for § 1983 liability.
Supervisory liability:
“Sergeant Davis received three prior complaints about Officer Smith’s use of excessive force during arrests, took no corrective action, and continued to assign Smith to patrol duties where similar encounters were foreseeable.”
This connects the supervisor to the harm through deliberate indifference to a known pattern.
What Bad Causation Looks Like
Too vague:
“The officers violated Plaintiff’s rights.”
Which officers? What did each one do? A judge will dismiss this.
Naming the boss without connecting them:
“Chief Williams is responsible for the police department and is liable for the actions of his officers.”
This is respondeat superior, which doesn’t work in § 1983. You need to show what the chief personally did or failed to do.
Group pleading:
“Defendants conspired to deprive Plaintiff of his rights.”
Who agreed to what? What did each person do in furtherance of the conspiracy? Group allegations without individual facts get dismissed.
Naming the department:
“The Irving Police Department violated Plaintiff’s Fourth Amendment rights.”
Departments generally aren’t suable entities separate from the municipality. Sue the city under Monell or the individual officers.
How to Build Causation in Your Complaint
1. List what happened chronologically
Write out exactly what happened, step by step. For each action, identify who did it.
2. Match each defendant to specific conduct
Create a mental (or actual) chart:
| Defendant | What they did | Constitutional violation |
|---|---|---|
| Officer Smith | Tackled plaintiff without warning | Excessive force (4A) |
| Officer Jones | Watched and did nothing | Failure to intervene (4A) |
| Sgt. Davis | Ignored 3 prior complaints about Smith | Supervisory liability (14A) |
| City of Irving | No use-of-force training on de-escalation | Monell — failure to train |
3. Use body camera footage
If you’ve obtained body camera footage, it’s your best causation tool. It shows exactly who did what, when, and to whom. Reference specific timestamps in your complaint.
4. Name officers by name, not badge number
Courts want names. “Officer Badge #4521” is okay as a placeholder if you genuinely don’t know the name yet (you can amend later after discovery), but get the real names through FOIA requests before filing if possible.
Causation at Different Stages
At the motion to dismiss: The court asks whether your complaint plausibly alleges that each defendant caused the violation. This is where vague or group pleading kills cases. Be specific in your complaint.
At summary judgment: Now you need actual evidence — not just allegations — connecting each defendant to the harm. Depositions, body camera footage, reports, and testimony.
At trial: The jury decides whether each defendant’s actions caused your injury. Causation is a question of fact, and reasonable minds can differ.
The “But I Don’t Know Who Did What” Problem
Sometimes you genuinely can’t identify which officer did what — you were face-down, it was dark, multiple officers were on top of you. This is common and courts recognize it:
- File against Doe defendants and amend after discovery reveals identities.
- Allege joint action — if officers acted together as a unit, you can argue they’re all liable for the collective use of force.
- Use discovery — interrogatories and requests for production can force the department to identify who was present and what each person did.
But don’t use “I don’t know” as an excuse for lazy pleading. Investigate before filing. Get the police report, FOIA the incident records, obtain body camera footage. The more you know before you file, the stronger your causation allegations will be.