I was discussing this in my alliance and was advised to place this suggestion here to see if it is something that is already being considered.
As we saw with Urgent Care Centre it introduced a transport mission from your UCC to a Hospital. With this new Police update, I feel there is an opportunity to create a similar mission but for policing with the detention van. For example, you get a transport request for a detention van to convey a prisoner from a Police Station to the nearest prison.
The whole idea surrounding this mission is persons taken into Police custody are often held to appear in court the next day. As it would be impractical to do the whole court concept in this game this mission could sim the result of a person being conveyed to court and held on remand in prison until trial etc.
I understand it may be a big ask but thought it would be good to suggest it.