Two folders come to mind, and both are at the bottom of your price range. Spyderco Manix 2 and Benchmade Griptilian. The Griptilian goes for around $100, unless you go for the version with the CPM 20 CV blade, then you will be out around $170. I believe the Manix 2 goes for $110.
I was going to suggest the Manix 2 as well. $100 for the S30V blade version on most websites. It's a very very tough SOB, with a very versatile blade shape that would be really useful to a cop, outdoorsman, or pretty much anything. I have the Manix 2 S110v G10 in my pocket as I type this. It will cost around $140 but you bump up to S110v steel, and also get skeletonize liners so it's lighter than the standard Manix 2, but without sacrificing strength. I'd bet it would make more sense for someone who's already carrying around a bunch of heavy gear.
I also have a BM Griptillian, and love it. It's been a loyal companion for about 10 years already.
The only gripe I have with the grip, is actually in its head-to-head comparison with the Manix. Think about it for a sec. Both cost right at $100 give or take a couple bucks. They have comparable locks as well. Fit/finish is comparable.
The Grip comes with 154cm and FRN scales.
The Manix comes with S30v and G10.
So for the same money, and all else being equal, it seems like better materials bump the Manix 2 into the "better bang for the buck" category.
That said, the Axis lock is easier to operate with just the thumb so you won't have to change grip position. That may be a big enough advantage for a police officer that it may give the Grip an edge.
Either way you can't go wrong.
Also check out the Spyderco Paramilitary 2. another very well respected classic.