>> reporter: to bring butler under control, the police officer indeed fired his taser, striking him in the chest. this taser is a consumer version that you can buy at any number of stores. the company says it utilizes the same technology in the weapons used by police. it works by pointing a laser beam embedded in the taser at the target and then pulling the trigger. according to the police report, three separate jolts of electricity went through butler's body. when it was all over, he was in full cardiac arrest, not breathing. paramedics revived butler, but his brain was deprived of oxygen, leaving him permanently disabled. his brother now takes care of him. >> once it's gone, it's gone. he can't remember any good times, birthday parties, christmas, any event. >> reporter: steve butler and his family filed a lawsuit not against the police, but against the maker of the weapon, taser