One of Us (1) Stingers : Season 4 Episode 12

A geeky inventor is suspected of being involved in credit-card doctoring, internet fraud, and making bombs. When Church is undercover at his house, a raid is carried out by gunnmen he believes are cops. And the cops-against-cops scenario is complicated when it appears the fraud suspect was involved with the death of Bill Hollister, who died in a bomb blast. Meanwhile, Stone finds himself recruited to undertake the most daunting of tasks when he is hired as a sniper by a bent cop.