Another tragedy: the state background check that could have stopped him from buying the murder weapon in the first place had been taken off the books by Colorado legislators just last March, CBS News Correspondent Jerry Bowen reports.
Colorado's abandoned system could have detected the temporary restraining order Gonzalez' estranged wife filed against him in the midst of their pending divorce.
Instead last Tuesday, Gonzalez warned a neighbor of trouble ahead: "he said 'somebody's gonna die,'" says neighbor Jason Wade.
Colorado's abandoned background check weeded out six times the number of unqualified gun-buyers that the federal system did. So, why was it dumped? Republican legislators decided it was too costly.
After picking up his daughters -- Rebecca, Katheryn and Leslie -- from their mother, he answered a newspaper ad offering guns for sale, and went to the home of a licensed gun dealer. As the girls played in the front yard, the gun dealer ran the required FBI check, which didn't note the restraining order. It hadn't been entered into the federal system. Gonzalez passed. The process took one hour:
Said Mike Knight of the District Attorney's office: "ATF has confirmed this was a legal transaction. A legal sale."
A few hours later, the Navy veteran used his new 9mm pistol to kill his daughters. Four hours after that Gonzalez pulled up in front of the police station.
Police believe Gonzales was suicidal when he killed the three girls. The bullets passed through the cab of the truck but no bullets were found on the ground or under the truck, indicating they were killed before Gonzales drove to the station.
Bill Palsulich of Lakewood, a federally licensed gun dealer, sold 9mm Taurus pistol and 30 rounds of ammunition to Gonzales for $375 about 7:30 p.m. on Tuesday while his daughters played in his front yard.
Palsulich had advertised three pistols in a newspaper ad, and conducted a background check with the Federal Bureau of Investigation. After an initial rejection, Gonzales was cleared and the gun changed hands.