The man accused of killing three people at a Colorado Planned Parenthood clinic left a decades-long trail of broken marriages, scant social connections and a reputation for religious zealotry that didn't match his yen for gambling and extramarital affairs.

New court documents and interviews reveal Robert Lewis Dear as an occasionally violent, fundamentalist loner who was known to nurse a grudge.

He had one for at least 20 years against the reproductive health organization he is accused of attacking, going so far as to put glue in the locks of a clinic in Charleston years earlier, eerily reminiscent of another gunman's efforts to glue shut a Wichita, Kan., abortion clinic's doors before killing a doctor there in 2009. The clinic in Charleston was not a Planned Parenthood facility at the time.

But still unknown is what caused Dear, 57, to allegedly escalate from petty vandalism to the fusillade he is accused of unleashing at the Colorado Springs office, where a law enforcement official said he rambled about "no more baby parts" after his arrest. Colorado Springs police have refused to disclose a motive for Dear's violence, but there's mounting evidence that Dear was deeply concerned about abortion.

Dear's ex-wife, Barbara Mescher Micheau, told The Associated Press on Wednesday that her former husband came home one day bragging about gluing the doors of a clinic. Micheau, who lives in Moncks Corner, S.C., said Dear never talked much about Planned Parenthood, although "obviously he was against abortion."

"He was always plotting revenge against people he felt did him wrong and you know it didn't take much for him to feel like somebody did him wrong," Micheau said. "So he would spend a lot of time trying to get back at people, trying to figure out ways to get back at people."

Angry and isolated

Micheau was Dear's second of three wives, and in the affidavit she filed to divorce him in 1993, she described him as angry and isolated.

Micheau said Dear had no friends, according to the document. He would listen to music on headphones for hours, ignoring her. He'd vanish for gambling trips to Las Vegas or Atlantic City and suddenly explode in anger at home, kicking her and pulling her hair.

"Rob's anger erupts into fury in a matter of seconds and is alarming," she wrote. "You have to constantly monitor his emotional state."

She added that he appeared devoutly religious.

He claims to be a Christian and is extremely evangelistic, but he does not follow the Bible in his actions. - Barbara Mescher Micheau, Robert Dear's ex-wife 

"He claims to be a Christian and is extremely evangelistic, but he does not follow the Bible in his actions," Micheau wrote. "He says as long as he believes he will be saved, he can do whatever he pleases. He is obsessed with the world coming to an end."

Dear's problems were evident even before their marriage ended. He jumped between jobs in fast-food management before joining the South Carolina electric company Santee Cooper.

There "he got in trouble a lot and played hooky a lot" before he eventually quit and became an artist's representative, selling prints wholesale to art galleries, Michaeu said.

"He liked the freedom of being his own boss and not having anyone to answer to," she wrote in the divorce complaint.

Money was tight and she said her former husband used his money for "personal pleasures," such as a motorcycle and an expensive gun, rather than their bills that piled up.

Previous arrest 

In 1992, after Dear and Micheau were separated, he was arrested in North Charleston, S.C., on a charge of criminal sexual conduct after a woman said he put a knife to her neck, forced her into her apartment and sexually assaulted her after hitting her in the mouth. No records show how the case was ultimately handled.

Dear also married Pamela Ross, who told The New York Times that he didn't seem overly zealous, standing against abortion but not dwelling on it. Court records show they divorced in 2001.

Neighbours who lived beside Dear's former Walterboro, S.C., home say he hid food in the woods as if he was a survivalist, warning neighbours about government spying. One neighbour put up a wooden fence separating their land because Dear liked to skinny dip.

Dear also lived part of the time in a cabin with no electricity or running water in Black Mountain, N.C.

About a year later, he moved again, having convinced another woman he met in South Carolina to live with him in his white trailer marked with a cross on a desolate stretch of land in Hartsel, Colo., ringed by Rocky Mountains.

Living more than 96 kilometres  west of the clinic in Colorado Springs, Dear rarely waved to neighbours, who saw him heading into the mountains on an ATV to gather firewood or stopping to get his mail at the post office.

Relatives of Dear's girlfriend, Stephanie Bragg, said they hadn't heard from her much since they moved. But her ex-husband, Gary Turner, was concerned.

"Gary said Stephanie was living in Colorado and that she was living off the grid, so he doesn't hear much from her," Bragg's former stepmother, Patricia Stutts, said. "It caused him a lot of distress."

Authorities have spoken with Bragg, who couldn't be located for comment Wednesday.