There are reporting requirements when a LEO is arrested and/or charged with a crime. I know my supervisor is notified if I get a speeding ticket (hasn't happened, yet

). If a LEO is arrested, they are put into segregation while in custody in a jail, for their protection. There is no need for most agencies to do a background check after hire unless something comes up, and due to CO POST guidelines, any certified employee facing charges has their agency notified and usually an IA investigation becomes necessary, even before actual charges are filed.
Not entirely accurate. DOC employees (IE: Prison Guards) are not required to be POST Certified. Even if they are, to maintain certification they have to undergo a mandatory number of hours of in-service training every year (new POST guidelines as of this year). I don't know how DOC would do this as most of their employees aren't certified, so it wouldn't make a whole lot of sense to have the certified members receive in-service training to maintain a certification they don't really need for the performance of their jobs (which includes firearms, driving, arrest control, and legal updates). Also, considering that non-certified LE (like detention specialists in county jails, DOC, etc) are not allowed to make lawful arrests, calling them LE is really a misnomer. As a certified and sworn LEO I do not consider DOC employees to be cops. I appreciate the work they do for the crappy pay they receive and the harsh realities they often face with sentenced felons, often dangerous felons, but cops they are not.