>> reporter: police say farook was an inspector for the depg. he abruptly left the holiday party after a dispute, came back, alongside malik. >> i heard rapid shooting. boom, boom, boom. >> reporter: investigators say the suspects came equipped dressed in tactical gear. family members receiving gut-wrenching text messages that an active shooting was taking place. >> people shot. waiting for cops. >> reporter: this was the frightening scene inside. >> are you ready? if you're not cool -- >> reporter: dozens of employees being led to safety by police officers. >> try to relax. try to relax. i'll take a bullet before you do, that's for damn sure. >> reporter: wounding 17 sure. prompting police and fbi and