Gunman in Colo. murder-suicide had been released hours before murder-suicide that left 4 dead

Investigators were unable to immediately determine when a gunman purchased a gun used to kill three people, including his ex-girlfriend, who was on the phone with a 911 dispatcher when she was killed.

Authorities say the gunman had just been released from jail on domestic violence charges before he shot and killed three people Tuesday and himself. Investigators searching the gunman's home found the original box the handgun had been sold in, but they did not find a receipt, and it was unclear when he bought it.

All were found dead in a home in unincorporated Weld County outside Longmont, about 35 miles north of Denver.

The gunman was identified as 31-year-old Daniel Sanchez.