Conspiracy (Criminal Law)

An agreement between two or more persons to commit a criminal act, combined with the intent to achieve that objective — punishable as a separate inchoate offense independent of whether the target crime is completed.

Elements / Test

Common law elements:

  1. Agreement between two or more persons (express or implied; proven by circumstantial evidence)
  2. Intent to agree AND intent to achieve the criminal objective
  3. Overt act in furtherance of the conspiracy (required by some jurisdictions; MPC for first-degree felonies requires no overt act)

MPC § 5.03:

  • Unilateral approach: A person is guilty of conspiracy if they agree with another person — even if the other party has no actual criminal intent (undercover officer scenario)
  • Common law required bilateral approach (genuine agreement between parties)
  • Renunciation defense (MPC § 5.03(6)): complete and voluntary renunciation + thwarting of success

Exceptions and Edge Cases

  • Pinkerton liability: Each co-conspirator is criminally liable for substantive offenses committed by any co-conspirator in furtherance of the conspiracy that are reasonably foreseeable (Pinkerton v. United States)
  • Wharton’s Rule: Where the target offense necessarily requires two parties (bigamy, adultery, incest, bribery), conspiracy charge requires more participants than the minimum needed for the offense
  • Gebardi rule: Victim protected by the statute cannot be conspirator
  • Buyer-seller: Mere purchase-sale transaction is not conspiracy to distribute
  • Scope — single vs. multiple conspiracies: Wheel (hub-and-spoke — needs rim to be single conspiracy) vs. chain (links with common interest = single)
  • Conspiracy vs. accomplice liability: Accomplice requires completion of underlying offense; conspiracy does not
  • Withdrawal: Complete withdrawal (affirmative act + communication to co-conspirators or law enforcement) before overt act — may avoid liability; does NOT unilaterally end conspiracy

Policy Rationale

Group criminal activity is more dangerous than individual crime; prevention rationale. But risks: overbroad collective liability; guilt by association; prosecutors use it to aggregate weak evidence.

Key Cases

CaseRule
Pinkerton v. United States (1946)Co-conspirator liability for substantive offenses in furtherance of conspiracy
Kotteakos v. United States (1946)Wheel conspiracy with no rim = multiple separate conspiracies; prejudicial to try together
People v. Lauria (1967)Mere knowledge of customer’s criminal use insufficient; stake in venture needed for supplier liability

Covered In