WOODLAWN, Md. (AP) — Baltimore County officials said Monday they’re examining a man’s interactions with authorities dating back 30 years after he killed three people, set fire to his home and was fatally shot by responding officers last weekend.

“We have a lot of questions,” Baltimore County Police Chief Melissa R. Hyatt said at a news conference in the aftermath of Saturday’s violence.

The man, Everton Brown, 56, had interactions with patrol officers, outreach officers and the crisis intervention team over many years, Col. Andre Davis said. Neighbors described threatening, erratic behavior and Davis said three peace orders had been filed against him.

Two guns were legally registered to Brown, Davis said, but Baltimore police seized one of them in 2010. Investigators believe Brown used the second weapon in Saturday’s rampage. Hyatt also said authorities would be looking back at forensic evidence from past years.

The shooting was the second recently with a mental health component in which multiple people were killed in the county, Baltimore County Executive Johnny Olszewski Jr. said. Those incidents reveal shortcomings in the current mental health treatment system and there’s a “need to take a serious look at gaps” to see what changes must be made, Olszewski said.

News outlets reported that Brown unsuccessfully sued the Department of Justice in 2012, alleging the agency had been running surveillance on him for more than five years and had unlawfully denied a public records request seeking records of said surveillance.