WILMINGTON, Del. — Authorities have confirmed that the gunman in a Delaware courthouse shooting that left three dead was the former father-in-law of one of the victims.

Delaware State Police today identified the gunman in Monday’s shooting as 68-year-old Thomas S. Matusiewicz of Edcouch, Texas.

Matusiewicz was the former father-in-law of Christine Belford, 39, who was fatally shot along with her 47-year-old friend Laura Mulford.

Matusiewicz, armed with a .45-caliber semiautomatic handgun, died after exchanging gunfire with police.

Authorities were awaiting the autopsy results to determine whether Matusiewicz was killed by police or shot himself.

State police said Belford and Mulford were at the courthouse for a child support arrears hearing for Belford’s ex-husband, David Matusiewicz. He was being questioned and was in custody on a federal probation technicality.