COLORADO SPRINGS, Colo. - The gunman believed to have killed four people at a megachurch and a missionary training school had been thrown out of the school a few years ago and had been sending it hate mail, police said in court papers Monday.

The gunman was identified as Matthew Murray, 24, who was home-schooled in what a friend said was a deeply religious Christian household. Murray's father is a neurologist and a leading multiple-sclerosis researcher.

Five people - including Murray - were killed, and five others wounded Sunday in the two eruptions of violence 12 hours and 65 miles apart.

The first attack took place at Youth With a Mission, a training center for missionaries in the Denver suburb of Arvada; the other occurred at the New Life Church in Colorado Springs, where Murray was shot by a security guard, though investigators said he may have died from a self-inflicted gunshot wound.

"Through both investigations it has been determined that most likely the suspect in both shootings (is) one in the same," police said in court papers.

Colorado Springs police said the "common denominator in both locations" was Youth With a Mission. The training center maintains an office at the 10,000-member church.

"It appears that the suspect had been kicked out of the program three years prior, and during the past few weeks had sent different forms of hate mail to the program and-or its director," police said.

Murray's relatives said they were grief-stricken and baffled.

"Our family cannot express the magnitude of our grief for the victims and families of this tragedy. On behalf of our family, and our son, we ask for forgiveness. We cannot understand why this has happened," they said in a statement read by the gunman's uncle, Phil Abeyta, who fought back tears.

In a statement, the training center said health problems kept Murray from finishing the program but elaborated little. Murray did not complete the lecture phase or a field assignment as part of a 12-week program, Youth With a Mission said.

"The program directors felt that issues with his health made it inappropriate for him to" finish, it said.

Police gave no immediate details on the hate mail. And the training center said that Murray left in 2002 - five years ago, not three - and that no one there can recall any visits or other communication from him since then.

Earlier Monday, a law enforcement official who spoke on condition of anonymity because he was not authorized to speak publicly, said it appeared Murray "hated Christians."

Investigators have not said whether Murray singled out his victims. But the two people killed at the church - sisters Stephanie and Rachael Works, ages 18 and 16 - frequented the training center, their uncle Mark Schaepe of Lincoln, Neb., told The Gazette of Colorado Springs. The two people killed at the missionary center were identified as Tiffany Johnson, 26, and Philip Crouse, 24.

Authorities searched the Murray house on a quiet street in Englewood on Monday for guns, ammunition and computers. No one was home when a reporter visited the split-level brick home early Monday. Murray's father, Ronald S. Murray, is chief executive of the Rocky Mountain Multiple Sclerosis Center in Englewood.

Matthew Murray lived there along with a brother, Christopher, 21, a student at Oral Roberts University in Tulsa, Okla. In a search warrant affidavit, investigators said Matthew Murray attended a home-based computer school and had worked at his computer for three to five hours a day for the past two years.

A neighbor, Cody Askeland, 19, said the brothers were home-schooled, describing the whole family as "very, very religious."