Getting OT out my force at the moment is like getting blood out of a stone.
It's got so bad that Officers are regularly starting their shift and having to take ownership of some debacle that the shift before have got involved in. It can be very difficult for a cop to report someone to court based only on a few paper statements that have been left on their desk (assuming you can read the writing). It's only a matter of time before a serious mistake is made and the guilty walk or the innocent get locked up, simply because an officer is being asked to deal with an incident that he/she has no involvement in.
All our OT has to get authorised by an Inspector, so if you are caught up in something you need to get authorisation before you are scheduled to finish. This might sound simple, but it's not always easy to say how long you will be interviewing or babysitting a custody at hospital or noting details for that high risk missing person.
Given the nature of the job, it's not always possible to finish on time, sometimes you can't just walk away (despite sometimes wishing you could!). On the other hand, I've got two court cases during my annual leave, where I'll sit around the court, get sent home without being called, and get paid double time. Why am I complaining again?