I have made a minor policy change in how promotions are attained.

Ranking from Rookie to Officer 1, is given by your Captain as a matter of course.. after review of cases and conduct, you’ll be granted this rank.
All other higher ranks, require you to apply to a senior officer (Sgt and above, depending on your current rank of course - it may just go straight to the Boss), who will advise the Captain of the application, and make the recommendation on readiness.
This will then be ICly granted or denied

for the record.. PD structure currently sits as follows

Captain
Lieutenant x 2
Sgt x3
Detectives x 6
Officers x unlimited

After a couple of recent demotions - largely due to inactivity in PD and DE in general, you'll see that currently filled are..
Captain - Me
Lieutenant x1 (Ben Stonage)
Sgt x2 (Martina Kells and Asuka Bellic)
Detective x 2 (Cas Whitesong and Sam Cooper)

so.. plenty up for grabs.. get working on your next promotion!!