Imperfect self-defense is a common law doctrine recognized by some jurisdictions whereby a defendant may mitigate punishment or sentencing imposed for a crime involving the use of deadly force by claiming, as a partial affirmative defense, the honest but unreasonable belief that the actions were necessary to counter an attack.
Not all jurisdictions accept imperfect self-defense as a basis to reduce a murder charge.
[1] The doctrine of imperfect self-defense has been defined as "an intentional killing committed with an unreasonable but honest belief that circumstances justified deadly force".
[3] Michigan recognizes imperfect self-defense as a qualified defense that may mitigate second-degree murder to voluntary manslaughter.
[5] In the U.S. state of California a defendant can be convicted of manslaughter but not murder when imperfect self-defense is successfully proven.