WOODLAWN, Md. (WJZ) –– Police are still investigating a shooting and explosion in Woodlawn early Saturday morning where investigators said 56-year-old Everton Brown ambushed and killed two of his neighbors in their home. They said Brown killed another neighbor and wounded a fourth person before police shot and killed him.

“We have a lot of questions right now… We’re looking back at 30 years of contact with this individual,” said Baltimore County Police Chief Melissa Hyatt.

Hyatt said, “I certainly think that we can infer that he had some type of mental illness. As for what his specific diagnosis or diagnoses were, that I don’t know right now.”

Vogel Hill had run-ins with Brown for more than 20 years.

He told WJZ Investigator Mike Hellgren that Brown was paranoid and delusional and becoming increasingly unhinged, believing his neighbors were spying on him.

Brown placed signs on his vehicle and home warning of FBI surveillance.

READ MORE: Victims Identified In Woodlawn Shooting Saturday, Police Detail Suspect's Attack

“He wasn’t cutting his grass, the signs started coming out, started yelling on the bullhorns, chasing people, harassing people,” Hill said.

Hill’s Ring camera captured video of the gunfire, people screaming and a panicked neighbor running for help.

“He was a pot boiling, and it was about to burst,” Hill told Hellgren. “And he burst… I don’t know what transpired in the last 72 hours to make him blow up like that because it never really got to that point before, but you knew it could.”

Baltimore County Police Col. Andre Davis said said Brown had two guns legally registered to him. “One of the weapons was seized in 2010 by the Baltimore City Police Department. The other handgun remained in his possession, and that is the weapon believed to be used in Saturday’s event,” Davis said.

According to court records, people living in this community filed peace orders against Brown. Hellgren reports one was filed just three days prior to the killings.

Hellgren also obtained a 2012 lawsuit Brown filed against the FBI claiming the agency was spying on him and demanding their records.

He detailed alleged aerial surveillance of his home. A federal judge dismissed it—fining no evidence of that surveillance.

“It’s not like we haven’t been saying anything. We’ve been saying something for 20 years. 20 years. And nothing was ever done,“ Hill said “What do you want us to do? The homeowners’ association says to tell the police. The police say we can’t do anything, you’ve got to talk to your homeowners’ association, so what are we supposed to do?“

Deborah Bordley told Hellgren both she and her husband had uncomfortable encounters with Brown over the years.

“He was a ticking time bomb,” she said. “When a helicopter came over, he acted like he was scared to death. He said, ‘Oh, you’ve got to get behind me. They’re spying on me. They’re spying on me.’”

She and other neighbors question why nothing was ever be done to get him help and stop the harassment despite numerous complaints—and before people lost their lives.

“What has happened from the ticking time bomb is that he has exploded and taken people’s lives away,” Bordley said.

WJZ was unable to reach any members of Brown’s family for comment.

MORE NEWS: 'We Just Woke Up With A Loud Bang' Neighbors Remember Victims Of Woodlawn Tragedy

Stay with WJZ on this developing story. To get breaking news alerts, download our app now