Complex sentence: Luke is one of the youngest Sergeants within the Constabulary, having risen to this rank after gaining a University degree in Criminology, he is aiming for the highest rank, a Chief Constable in charge of the entire force.
Split into simpler sentences: Luke is one of the youngest Sergeants within the Constabulary. Having risen to this rank after gaining a University degree in Criminology, he is aiming for the highest rank, a Chief Constable in charge of the entire force.