To unlock the 4th police option and further that story, I believe you need to further the Ginger path first. Go to Chloe on the map and drive her home. In version .54 there's now the option to approach the van in the parking lot. There you'll find Ginger and her annoying brother. Once you finish the Ginger question, she'll be added to the cop options.The only problem I have is the "police story" I cant go past Annie's 3 speech options (tried selecting all cops with no luck to get storyline to continue) and I don't know, if it is a clitch to not continue past the Annie option "say she is too sexy to be a officer" or if it is a future update to continue story line.
There's a fair chance I don't know what I'm talking about, so good luck.