Story Highlights• NEW: School gunman sent 14-page letter mentioning expected death, officials say
• Police say Duane Morrison, 53, molested all six hostages in Colorado high school
• Slain student Emily Keyes sent text message to family during Wednesday's siege
Adjust font size:
BAILEY, Colorado (CNN) -- The gunman who sexually assaulted hostages at a Colorado high school before killing a student and then himself wrote a 14-page letter to a relative that apologized for events to come, officials said on Friday.
Although the handwritten letter mentioned suicide and Morrison's pending death many times, it said: "This is not a suicide note," Park County Sheriff Fred Wegener told reporters.
The letter appears to have been written over several days, he added.
Wegener said the letter was postmarked September 27 and didn't refer to Platte Canyon High School in Bailey, where Duane Morrison took six students hostage on Wednesday, or any other school.
The letter also didn't mention harming anyone nor did it refer to anyone in the Platte Canyon area, Wegener said.
The letter was mailed from the post office in Shawnee, the town down the road from the school, and arrived in the relative's mailbox the next day, when Morrison infiltrated the school.
"It (letter) doesn't tell me a lot of why," Wegener told reporters. "He probably intended to kill both the young ladies, then kill himself -- or have us shoot him."
Before killing 16-year-old Keyes and then himself, Morrison had held her and five other girls hostage, police said.
All the girls were molested, said Wegener. The sheriff didn't know "how much or to what degree."
In an exclusive interview with the Rocky Mountain News, Lynna Long, a 15-year-old sophomore, described being one of the six hostages.
"He told us to get up and line up against the blackboard, our faces toward the wall," the paper quoted her as saying. "Then he fired a shot. I think it's because some people weren't complying fast enough, and he was trying to scare us."
She said that Morrison had told the students he had enough explosives to blow up the whole school, made the rest of the males leave, and then sexually assaulted the girls as they faced the wall.
Authorities found a .357 Magnum and a Glock pistol on Morrison's body. U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives had traced one of the guns to the Colorado relative who received the letter, Wegener said.
Before he took the girls hostage, Morrison had gone up to a male student and asked about the identities of "a list of female students," Wegener said. He didn't know which, if any, of the girls he held in a classroom were on that list.
Morrison killed Keyes with a single shot to the back of the head, Wegener said, as she tried to escape during the SWAT team's raid into the classroom where she and another student were being held. By then he had already released the other four students.
Wegener has said he ordered the classroom raid to end the three-hour standoff after hearing Keyes and the other hostage screaming.
Morrison was using Keyes as a human shield when the officers stormed in, Joe Morales, executive director of Colorado's Department of Public Safety, told reporters Thursday. (Watch sheriff reveal what happened after the gunman was pinned down in a classroom -- 3:05
Keyes was taken by helicopter to a Denver hospital where she was pronounced dead.
On Thursday police released her photo and the last text message she had tapped out to her family as she was being held: "I love u guys." (Full story)
Bailey is not far from Columbine, where two students killed 12 classmates and a teacher before killing themselves in 1999.