One time we let our kids watch cops.
I asked them later what they'd learned. My son said...that there are a lot of stupid people who never learned to shut up, listen, follow directions and sort it out later.
It was a great lesson for them.
When my children were small I sat down with them and observed them as they watched COPS episodes. We would talk about how there are really mean nasty people in this world, and what they looked like and what they did.
COPS is a true life object lesson for children to know that evil stupid people are out there and they better watch out.