Agreed, but only when they've been murdered.
In the case of the policeman and the thief, the police is not supposed to murder, but to righteously kill, so we can't use "asesinar" there.
By the way, the Diccionario Panhispánico de Dudas says that "
fue matado" is normally substituted for "
fue muerto" despite the fact that both participles belong to different verbs, because the verb "morir" used to be causative in archaic Spanish.
