Some LEO's in Oklahoma are issued select fire rifles, like troy said mostly swat members. But my grandfather is a Oklahma street crimes deputy, and is a member of the drug task force. He was recently issues a select fire AR. I have got to shoot it a handful of times, I am lucky that we live out in the country and have a private gun range, so I can shoot it anytime he is home and willing to walk down to our range with me, that is if I have to money and ammo to feed it.
It is kinda scary though, talking to some of the guys he works with that were also issued select fire rifles. Most of what they do is buying drugs, so that they can get the proper warrants. These rifles are for when they are serving a warrant,, which is alot of times these days. I asked why they need full auto capabilities, and mentioned that it seems like overkill to me. Then I asked what if they had to actually fire their rifles in defence while serving the warrant, what if there is innocent bystanders close by. I was told by a cople of them that they are not concearned with the safety of the bystander, they will still use full auto even if the innocent person is shot by the police, they are only concearned with making sure they(police) are not shot by the drug dealer.
I was actually told that by a couple of the drug task force guys that are carrying department issued full auto's. It really scares me that there are LEO's out there that are not concearned if they shoot an innocent person as long as they are safe. I like shooting my grandfathers department issued full auto, but I think it is a horrible idea for any LEO's use full auto burst's in a public setting where people are around.