capital offence/crime
From Longman Dictionary of Contemporary Englishcapital offence/crimecapital offence/crimeSCLKILLan offence that is punished by death → capitalExamples from the Corpuscapital offence/crime• Loss of privileges in peacetime; in war, a capital offence.• The word from Lilongwe now is that Chihana will be charged with sedition, a capital offence.• It is capital crime, and a black disgrace to the races of civilized mankind.