Wiktionary
n. 1 A crime for which the maximum penalty is capital punishment. 2 A crime for which the maximum penalty is life in prison without parole.
WordNet
n. a crime so serious that capital punishment is considered appropriate
Usage examples of "capital offense".
Striking a petty officer wasn't the capital offense striking an officer was, but it was close enough, and—.
The commandant of the Lewis and Clark had hauled him aboard for the crime of excess curiosity, a crime that had just missed being a capital offense.
Ordering soldiers to kill in war other than in self-defense is now a capital offense.
Schoolteacher-lost that job when they caught me teaching the kids the raw truth, a capital offense anywhere in the Galaxy.
Under the Manticoran Articles of War, forcible rape was a capital offense whether force was actually used or simply threatened, and given the situation here on Hell, any demand a Black Leg made had to be considered to be backed by the threat of force.
Confused by the Bible's portrayal of Jezebelit appeared to contend that cosmetics were witchcraft, and coquetry a capital offense Ellen Cherry had asked Patsy (lines of communication with her parents had been reopened approximately six months after she settled in Seattle) what she knew about the queen's sordid reputation.
Certain types of loudmouthism should be a capital offense among decent people.
The clothing would have been a capital offense on Ramala, Damdin's home world, and utterly unacceptable on Asgard or Sossann.