It is marketed as LEO by Winchester. The Black Talon ammo was used in a high profile shooting in California many years ago and the mainstream media and anti-gunner types threw a fit about the stuff so Winchester voluntarily took it off of the market so that there wouldn't be a movement to ban it. (They hoped) They improved it and re-introduced it for law enforcement sales only under the new name "Winchester Ranger" and the rest is history.
But it's not against the law to own unless there are local laws against it. I don't think there are any in California that I'm aware of. New Jersey has a law against hollowpoints and I think someplace in NYS does to, probably NYC. What happens is sometimes departs order some and then change their minds or just don't use it all and it ends up on the civilian market. I don't know how else some people get it, but one guy I buy from told me he can order it direct from the factory anytime Winchester is making it.