will cut out pieces of the picture and actually sell it. >> narcotics inside prison can be sold for almost 30 times their street price. a ounce of heroin that might cost $800 can be broken up and sold here for thousands. >> get the house, the guy was selling dope out of the house, so, there is probably dope in that building. >> to crackdown on the gangs' narcotics network, corcoran has formed a highly trained intelligence gathering team called the investigative service unit. our cameras were allowed access to follow this unit, along with a local k-9 team, while they set out on a surprise contraband bust. searching inmates' cells for drugs, weapons and gang paraphernalia. >> nobody else knows we're coming. the captains don't know. nobody knows we are coming. so, this is going to be a complete surprise to staff and everybody. >> head of the isu, sergeant john montgomery knows that inmates will destroy or hide the contraband if they find out