Delaware Courthouse Shooting Update: Gunman ID'd as ex-father-in-law of one of the victims

New Castle County Courthouse, in Wilmington, Del., where police say three people were fatally shot the morning of Tuesday, Feb. 11, 2013.
Jenn Bernstein via CBS Philly

(CBS) WILMINGTON, Del. - A law enforcement official has confirmed that the gunman in a shooting at a Delaware courthouse Monday that left three dead was the ex-father-in-law of one of the victims, CBS Philly reports.

The station reports the gunman has been identified by law enforcement as 68-year-old Thomas Matusiewicz.

Matusiewicz is reportedly the former father-in-law of Christine Belford, who police said was fatally shot Monday. The Associated Press has identified the other victim as Belford's neighbor, Laura Mulford.

Matusiewicz exchanged gunfire with police and also died. It was not immediately known if he was killed by police or if it was a self-inflicted gunshot wound, according to CBS Philly.

The New Castle County Courthouse remained closed Tuesday as a team of investigators arrived at the building Tuesday morning and continued to collect evidence, the station says.

According to investigators, the suspected gunman entered the lobby of the courthouse Monday morning, pulled out a gun and opened fire - targeting Belford.

Two Capitol building police officers were wounded during the shootout and were taken to Christiana Hospital with non-life threatening injuries. They were treated and released, according to CBS Philly.

Authorities believe Matusiewicz acted alone, but they searched all 12 floors of the courthouse as a part of the investigation. Although the motive for the shooting remains under investigation, Delaware Attorney General Beau Biden said during a Monday afternoon news conference that it was not a random act and according to preliminary information, appears to have been the result of a custody dispute that has lasted in the courts for several years.

Belford, of Newark, Del., was the former wife of David Matusiewicz; Thomas Matusiewicz's son. David Matusiewicz was scheduled to be at the courthouse Monday for a custody hearing, but it was not immediately known if he was at the building when the shooting happened.

However, authorities say David Matusiewicz was held Monday on a federal probation technicality, and he is scheduled for a hearing Tuesday.

An autopsy is scheduled to be performed on Thomas Matusiewicz on Tuesday, according to the station.

Police are urging any eyewitnesses to the shooting to call: 302-834-2620 Ext 0.

More on CrimesiderFeb. 11, 2013 - Delaware Courthouse Shooting Update: Suspect, wife, and one other killed in morning gunfight, police sayFeb. 11, 2013 -Delaware Courthouse Shooting: Three people shot at Wilmington courthouse, police say