More details have emerged about the man who fatally shot three people on the streets of Colorado Springs, with a book written by his mother documenting his struggle with addiction.

The gunman was identified by authorities as 33-year-old Noah Jacob Harpham, who lived just steps from where his first victim was slain on Saturday. He was a recovering alcoholic who posted an online video two days earlier expressing displeasure with his father for allegedly falling under the sway of a particular preacher.

Witnesses of the shooting said Harpham had a rifle in one hand and a revolver in the other when he first killed a bicyclist. He then calmly walked less than a mile and fatally shot two women on the porch of a sobriety house. Harpham was then killed in a gun battle with police.

A motive for the downtown shootings in broad daylight remains unknown, and Harpham left few clues in blog posts and on social media. He gave no indication of the violence to come in the video posted two days before the shootings.

His mother, Heather Kopp, a freelance writer living in New York, described his long struggle with addiction in Sober Mercies: How Love Caught Up With a Christian Drunk, a book also about her own battle with alcoholism.

Authorities have not said whether there was any link between Harpham’s substance abuse problems and the fact that two of his victims were in addiction recovery.

Colorado Springs police released no new details about the shooting and refused to identify those killed pending the completion of autopsies. The El Paso County sheriff’s office said four officers fired at Harpham but that they were not wearing body cameras, and their squad cars were not equipped with dashboard cameras.

A fuller picture of Harpham emerged in details from his mother’s book, in which she described him as “introverted and moody” and turning to drugs and alcohol around the time he gave up on college. Kopp said Harpham, who was living in Eugene, Oregon, at the time, “struggled just to live and keep a job”. It said his family was so worried about him they staged a “mini intervention”, but their efforts failed.

He completed a three-month program in California, but drank on his first night out, Kopp said. “Noah loved and hated all of us in equal measure,” she wrote. “In Noah’s mind, he was the loser child, the burnt piece of toast in the bunch.”

During a visit to his family’s Colorado Springs home years ago, he drank too much, became angry and “exploded”, Kopp said. His mood had become “so toxic it was scary”.

His mother and stepfather urged Harpham to move in with them. In Colorado Springs, she said, he found work as an insurance agent and met an Alcoholics Anonymous sponsor regularly.

His mother wrote that he seemed to improve under their roof and eventually moved into his own place. She said he began helping other addicts.

In a YouTube video posted on Thursday, Harpham questioned what he called his father’s involvement with Rev Bill Johnson and the Bethel church in Redding, California. The church is part of a stream of Pentecostalism that emphasizes signs of God’s miracles and revelations in modern-day life, along with supernatural healing. Johnson and his church have come under criticism from conservative Christians who say Johnson promotes teachings beyond the boundaries of mainstream Christianity.

Efforts to reach Harpham’s father, Thomas, and officials with the Bethel church by telephone on Monday weren’t immediately successful.

Kopp and other relatives did not return messages seeking comment. Benjamin Broadbent, lead minister of the First Congregational Church of Colorado Springs, released a statement he said was provided by Harpham’s family, saying they were shocked and saddened and requesting privacy.

Family and friends identified the women killed as Christy Galella and Jennifer Vasquez. Harpham first shot Vasquez, who was sitting outside the house, causing Galella to open the front door to see what was going on, said Galella’s uncle, Chris Bowman.

Neighbor Teresa Willingham said the third victim was a cyclist whom she and other residents did not recognize.

Associated Press contributed to this report

