1) Sites dedicated to helping felons when they get out. Eg. jobs, housing, pardon, addiction services etc. There are many agencies that do this.
2) Criminal defense lawyers. Felons are prime customers for this type of lawyer.
3) Companies that provide products and / or services to law enforcement agencies ranging from capturing felons, incarcerating them to executing them (the US does have the death penalty).
4) Certain Entertainment sites
As for the tld with the exception of .com among the best for this name. The us has a hugh prison population. I say wait for .us to establish itself and this name will have value.