Sure, but I think the issue is that even when they are empowered as law enforcement, there's not much they can do if the DA isn't going to prosecute these cases

Sure, but I think the issue is that even when they are empowered as law enforcement, there's not much they can do if the DA isn't going to prosecute these cases. My understanding is that they can pursue drug crime or break up organized fencing operations. But at the low level most of these train robberies are happening they probably don't waste their time.