'He looked really mad'

Eyewitnesses to the Colorado high school siege, which left one teenage girl hostage dead along with the gunman, have been giving US media dramatic details of how it began:

Zack Barnes, 16, was in a neighbouring room with his class and recalls how the lights were turned out and people sat in silence in the dark for about 20 minutes before police guided them out.

"I was just praying it wasn't a mass killing," he was quoted by The Associated Press news agency as saying.

Marina Escobedo was also in a room close to the gunman, who has been identified as Duane R Morrison.

"This was the scariest thing I have ever been in," she told the Rocky Mountain News.

"I was freaking out. Everyone was freaking out. We were in class and heard on the intercom 'Code white'. First we were thinking it was just a drill, but then we realised it wasn't... He was in the room right next to us."

'Looking really mad'

Other students quoted by the Rocky Mountain News only realised they had seen Morrison at the school later when they saw his photo in the media.

Two unnamed girl students had seen him sitting in a car in the school parking lot an hour before the attack began, drinking what appeared to be liquor.

Male students Roman Tucker and Bobby Wright said they were leaving the school around 1045 (1645 GMT) when they spotted a man in a yellow Jeep in the lot.

The man looked at them but did not acknowledge them, the paper says.

His windows were rolled up and the back of the Jeep was filled with junk, they were quoted as saying

"He just stared at us and went back to looking at the school. He looked really mad," Roman said.

When he saw the photo of Morrison on Thursday morning, he recognised him. "I was like, whoa, that's the guy," he said.

False account

Another student at the high school, Cassidy Grigg, went on US television channels NBC and ABC to give an account of how the gunman had chosen his hostages and threatened him personally.

However, the boy's mother, Larina Grigg, later announced that her son had lied, Colorado newspaper The Rocky Mountain News reports.

"Cassidy has never been dishonest in his life, but in this matter he wasn't truthful," she said on Thursday afternoon. "He was not in the room with the kids. He wants to say he's sorry. I know and he knows he made a huge mistake."