## Facts

- Edward Klein, a dentist living across from Sims Drug Store in Springfield, observed two men, Napoleon J. LaDue and John Savageau, breaking into the store at night on August 1, 1973.
- LaDue and Savageau attempted entry with a tire iron, then smashed a window with a stone and entered through the broken opening intending to steal money and cigarettes.
- Klein telephoned police and later went outside armed with a pistol.
- Klein shot and wounded both men after the break-in.
- The central dispute was whether Klein shot the men while they were fleeing and not posing a deadly threat (Commonwealth’s evidence) or fired in self-defense as they approached him threateningly (Klein’s account).

## Issues

1. Whether Klein was entitled to a directed verdict of not guilty because the evidence established self-defense as a matter of law, or at least failed to permit a finding beyond a reasonable doubt that his use of deadly force was unlawful.
2. What legal limits govern a private citizen’s use of deadly force to arrest a felon, and whether Klein’s shootings were justified as part of a citizen’s arrest of burglars.
3. Whether newly articulated limitations on citizen use of deadly force to arrest felons should apply retroactively to Klein’s pre-decision conduct.

## Decision

- The court held Klein was not entitled to a directed verdict on self-defense because the evidence, viewed favorably to the Commonwealth, permitted findings that he did not act in self-defense or that he used excessive force.
- The court adopted Model Penal Code § 3.07 as the law governing a private citizen’s use of deadly force to arrest a felon in Massachusetts.
- Under the newly adopted standards, Klein’s use of deadly force to stop fleeing burglars was not justified as a citizen’s arrest because the burglars’ conduct did not threaten death or great bodily harm.
- Because the court was announcing these governing rules for the first time in Massachusetts, it declined to apply them retroactively to Klein and ordered judgments of not guilty entered on both indictments.

## Legal Principles

- A defendant is not entitled to a directed verdict on self-defense when the evidence would allow a rational jury to find either lack of self-defense or use of excessive force.
- A private citizen’s use of deadly force to arrest a felon is tightly limited under MPC § 3.07, including that deadly force is generally impermissible for property felonies absent circumstances involving deadly-force threats or comparable risks of serious harm, and subject to necessity-type constraints.
- When a court announces a new, material constraint on justified force in criminal law, it may apply the rule prospectively to avoid retroactive criminal liability based on standards first declared in the defendant’s appeal.

## Conclusion

Massachusetts restricted a private citizen’s authority to use deadly force to arrest felons by adopting MPC § 3.07, but because those restrictions were newly announced, the court did not apply them to Klein’s earlier conduct and ordered acquittals despite evidence sufficient to support the jury’s guilty verdicts under the new framework.


Commonwealth v. Klein, 372 Mass. 823 (1977)