A] n officer, at common law, was not authorized to make an arrest without a warrant, for a mere misdemeanor not committed in his presence

"If the officer had no right to arrest, the other party might resist the illegal attempt to arrest him, using no more force than was absolutely necessary to repel the assault constituting the attempt to arrest."

In Bad Elk, the Supreme Court explained that "At common law, if a party resisted arrest by an officer without a warrant, and who had no right to arrest him, and if in the course of that resistance the officer was killed, the offence of the party resisting arrest would be reduced from what would have been murder, if the officer had had the right to arrest, to manslaughter."

—noting common-law pedigree of state statute permitting warrantless arrest "[f] or a public offense committed or attempted in [officer's] presence

For example, if the police illegally fired warning shots at a person, would that person be shielded from arrest and prosecution if he fired back and killed someone

—reviewing common-law principles and federal and state statutes authorizing warrantless arrests; reversing a murder conviction based on trial court's failure to instruct jury on defendant's right to resist an illegal warrantless arrest

—the Supreme Court held that the killing of a police officer may be reduced froni murder to manslaughter where the perpetrator, whose intent was to resist an unlawful arrest, lacked the requisite malice aforethought.

At common law a person could use "no more force than was absolutely necessary" to resist an unlawful arrest.