Being in LE is definitely more dangerous than being in any kind of aviation. I was a city cop for 8 years. The quality of life is much, much different. You'll be home every day, but working 8 to 10 hour shifts. Some departments rotate shifts - then you'll be on a regular day schedule 1/3 of the time, and not see your family much when you're on afternoons, or much on the 3rds. If you don't like being up all night, 3rd shift will kill you. If you get permanent shifts, then contstant 3rds (11pm - 6am) will kill you too. Permanent 2nd, you'll never see your kids. They come home from school when you're going to work, and will be asleep when you come home.
The emotional stress of the things that you deal with - child abuse, spousal abuse, people mangled in car wrecks, shootings, fires - is not something to be taken lightly. Cops have one of the highest divorce rates out there.
You'll probably have to work most holidays too. So forget travelling to see family most holidays.
It can be very rewarding, though, too. Taking bad, mean nasty people off the street is a great thing. Helping people sleep better at night when they're afraid, and hear noises in their houses or yards is a good thing too.
If you really want to do it, I would recommend a large city or federal agency where you have the chance to get off the street after a few years and start investigating or training. Nobody wants to be the first one though the door continuously when you're 45, 50, etc. Or grabbing people out of cars, wrestling with dudes on the side of the road when they're 20, 30 years younger than you.
Think long and hard about it.