PRINCIPLE: Nothing is an offence, which is done by a person who is bound by law to do it.
FACTS: 'A', a police officer, without warrant, apprehends 'Z', who has committed murder.
The Principle says that nothing is an offence done by a person who is bound by law to do it. There are two kinds of offenses- cognizable and non cognizable offences. Police officers need to have an arrest warrant before arresting any alleged person in any offence but for the offences falling in the former, there is no need of an arrest warrant. Section 154 of Criminal procedure code gives power to the police officer to arrest anyone alleged to commit a cognizable offence without warrant after registering FIR( First Information Report). Murder’ as defined under Section 302 of IPC is a cognizable offence. Therefore, ‘A’ was authorized and bound by law to arrest or apprehend Z who has committed offence of murder which is a cognizable offence.