. >> reporter: his name is frank calabrese jr. and his father frank sr. is serving multiple life sentences for killing 13 people while stealing and loan sharking millions as a made man in the outfit, a chicago mob notorious since the days of al capone. did he have a signature? >> yeah. when he was killing, he wanted to make sure you were dead. so, he loved to strangle you and cut your throat from ear to ear. >> reporter: just to make sure? >> just to make sure. >> reporter: seeing this family in this setting, you'd never know that she was once an unwitting mob wife. somebody asked, what does your husband do, what would you say? >> he worked for the city. which he did. ignorance was bliss for me. >> reporter: and if you met him on the street, you'd never imagine that within the outfit, he went from respected enforcer to reviled rat by helping the fbi put his own father away for life. >> i call myself a lot of things but i don't call myself a rat and why? rats run and hide. i don't. i can't run and hide. i'm a cooperating witness. i'm a turn coat. i'm a bad