^^^Carrying a fixed blade in uniform is no easy task to say the least.
You are in a police uniform, not a soldier's uniform. Carrying it openly is not an option in my opinion. Weapon retention is a big concern, and I can't protect a knife and my sidearm at the same time.
The BK17 is great in the woods when it and a Leatherman pouch are the only thing on my belt. In a police uniform its another story.
I think his best bet is a Kabar TDI tucked away somewhere snug. They make a large version now which I have considered trying. I carried the original TDI years ago, but I now ride a bicycle on duty and it was not comfortable when bent over in a riding position. I had to ditch a lot of goodies due to very limited space on my person and only a small saddle bag on the bike. Just a small clipboard and a few report forms, and a few extra batteries for my lights are not easy.
Honestly just the fact that I am able to squeeze in a concealed backup handgun is pretty good as far as I am concerned. I don't have room for a large knife. I carry a Benchamde Contego clipped in my offhand pocket. It is nothing but a fighter, but its a good one. I carry a small Victorinox inside my pocket for utility tasks.
There are several different carrying options, and with a little research you can find them all.
http://www.kabar.com/knives/detail/48