Dallas (CNN) Hours before a sniper shot him during a standoff with police, James Boulware was helping out at his father's house, mowing the lawn and promising to come back again soon.

Now, Jim Boulware sobs as he sits in his home, knowing his son will never return. The federal agents who brought bomb-sniffing dogs as they searched for evidence are gone. So is the armored van his son bought on eBay. And for the father of the man who died after unleashing a hail of bullets at police headquarters Saturday, a devastating reality is beginning to sink in.

"Every one of us has a breaking point. ... He hit his," Jim Boulware said.

Boulware says his son was boiling with anger over a custody battle and blamed police for taking his son away.

"I tried to tell him the police didn't do it," he said. "The police were doing their job to enforce the laws."

When his son stopped by recently, Boulware says, he saw a strange-looking van out back. His son told him he'd bought the armored van on eBay and picked it up in Georgia this month so he could have somewhere to sleep.

"He said, 'Dad, I have lost my house, my tools, my son. I'm going through every dime I've got. I can't find a job because I got domestic violence on my record.' He said, 'I've lost everything.' "

'This suspect meant to kill officers'

Police say the gunman unleashed a barrage of gunfire on Dallas police headquarters and planted explosives outside the building early Saturday before leading officers on a chase that ended at a restaurant parking lot.

Before he was shot, police say, the man ranted to 911 dispatchers by phone, identifying himself as James Boulware and saying that police were responsible for taking his child away.

Police called him back, eventually allowing SWAT officers to negotiate.

But the man opened the door of his van, shot at police again and grew increasingly hostile and agitated when called on the phone.

After he made more threats, police snipers shot him through the windshield.

Officials have placed 14 police officers involved in the standoff on administrative leave while authorities continue their investigation into what happened, police said Sunday

The suspect had told police that the van contained explosives, prompting them to call a bomb squad to inspect it.

"We believe this suspect meant to kill officers," Police Chief David Brown said. "We barely survived the intentions of this suspect."

Photos: Attack on Dallas Police Photos: Attack on Dallas Police The van used by a lone shooter to attack and then flee Dallas Police Headquarters catches fire outside a fast-food restaurant on June 13, in Hutchins, Texas. Authorities used controlled charges to discharge pipe bombs in the van after the shooter reportedly unleashed multiple rounds and planted explosive devices around the station before leading police on a chase that ended in a standoff in the parking lot of the restaurant. Hide Caption 1 of 15 Photos: Attack on Dallas Police Police use a robot to gain access to the suspect's van, which authorities believed was rigged with explosives. Hide Caption 2 of 15 Photos: Attack on Dallas Police Evidence markers sit by bullet casings on a sidewalk near the police headquarters. Hide Caption 3 of 15 Photos: Attack on Dallas Police FBI evidence response team members look down at a piece of marked evidence on the street in front of Dallas police headquarters. Hide Caption 4 of 15 Photos: Attack on Dallas Police A sniper and a tactical officer take up positions on the shoulder of Interstate 45 at Dowdy Ferry Road. Hide Caption 5 of 15 Photos: Attack on Dallas Police Police setup a remotely operated robot during the standoff. Hide Caption 6 of 15 Photos: Attack on Dallas Police A Dallas County Sheriff's officer directs traffic at the intersection of Dowdy Ferry Road and Interstate 45. Hide Caption 7 of 15 Photos: Attack on Dallas Police Police block the intersection of Dowdy Ferry Road and Interstate 45 near where the suspect was barricaded in a van. Hide Caption 8 of 15 Photos: Attack on Dallas Police Police officers walk down Belleview Street on June 13, one block away from Dallas Police Department headquarters, as they search the area after the early morning attack on the building. Hide Caption 9 of 15 Photos: Attack on Dallas Police Dallas police officers search Belleview Street near the headquarters. Hide Caption 10 of 15 Photos: Attack on Dallas Police Officers check a newspaper rack. At least two pipe bombs that were found outside the police headquarters after the initial shooting. Hide Caption 11 of 15 Photos: Attack on Dallas Police A resident walks his dog past police blocking the road near Dallas Police Department headquarters. Hide Caption 12 of 15 Photos: Attack on Dallas Police Dallas police released a photo of a squad car struck by bullets. No officers were injured. Hide Caption 13 of 15 Photos: Attack on Dallas Police Dallas police posted on Twitter this image of damage to the headquarters. Hide Caption 14 of 15 Photos: Attack on Dallas Police Bullet holes can be seen in the windows of the headquarters. Hide Caption 15 of 15

Mom: 'I kept hoping he would straighten himself up'

Now, the van is a burned-out shell after investigators detonated the explosives that had been planted inside.

Authorities say James Boulware had a record of domestic violence and custody issues. He also had a long history of mental illness, and his family struggled to handle it, according to his mother.

She said she'd considered having him committed but worried that might drive him over the edge rather than helping.

"I really kept hoping he would straighten himself up," Jeannine Hammond said. "But he couldn't. He really couldn't."

In April, Hammond won custody of her grandson from her son. During the trial, she said, her son was delusional, ranting in court and telling the jury he knew where Osama bin Laden had been hiding before U.S. forces killed the al Qaeda leader. It's something he'd done before, she said, claiming to loved ones that he knew about news events before they happened.

In the past, his mother said, he'd talked about wanting to shoot up a school, but not hit any students, so that officials would learn they needed armed guards to protect children.

"We all said no. And he really did not like that we did not agree with him on that," she said. "And that was the first indication I had that he ... might be going down the route he went down (Saturday)."

Still, Hammond said, she expected that if her son turned violent, she would have been the target.

"I would have thought that I would have been the one that he singled out, since I got custody of his child," she said.

A Dallas County judge said she had extra security put in place after hearing the custody case.

"He was always a threat to us," family court Judge Kim Cooks said. "We just didn't know what he would do or when he would do it or what was going to happen. ... He would look at you as if he wanted to kill you."

Father: Custody battle devastated son

Jim Boulware says police had a right to respond the way they did, but that's only part of his son's story.

"He pulled a stupid act. But what led up to that?" he said. "You don't know what it's like to lose custody of your son. He loved that boy."

It's a feeling Boulware is starting to experience, too.

"Now," he says as he blinks back tears, "I lost a son."