A 24-year-old suburban Denver man who "hated Christians" is believed to commit deadly shooting sprees at a megachurch and a missionary training school.
The official, who spoke on condition of anonymity because he was not authorized to speak publicly about the investigation, identified the gunman as Matthew Murray, the son of a neurologist who is a prominent researcher on multiple sclerosis.
Five people - including a gunman - were killed, and five others wounded Sunday in the two eruptions of violence 12 hours and 65 miles (105 kilometers) apart.
The first attack took place at a youth missionary training center in the Denver suburb of Arvata; the other happened at the New Life Church in Colorado Springs, where the gunman was shot and killed by a security guard.
The law enforcement official said Murray was believed to be the gunman in both attacks. Murray did not appear to have a criminal history but "hated Christians," the official said. The official did not know Murray's religion, if any.