TEXAS, United States (AP) — The suspect arrested in the ambush shooting of a San Antonio police detective has said he was angry about a child-custody battle and “lashed out at somebody who didn’t deserve it”.

Otis Tyrone McKane was being led by police to the Bexar County Jail late Monday when he told reporters that he was angry with the court system for not letting him see his son and took it out on Detective Benjamin Marconi.

“I’ve been through several custody battles, and I was upset at the situation I was in, and I lashed out at someone who didn’t deserve it,” McKane said. He said he wanted to apologize to the family of the slain officer.

McKane, 31, of San Antonio, was arrested on a capital murder charge Monday afternoon in the fatal shooting of Marconi. 

The detective was shot as he sat in his squad car Sunday after making a traffic stop. Authorities have said a gunman walked up to Marconi’s driver’s-side window and fired.

It was one of several weekend attacks against law enforcement in multiple states.

Read:Four US police officers shot in three cities

A San Antonio detective and officers shot in Missouri and Florida were conducting routine tasks Sunday when they became the targets of violence. Marconi was writing a traffic ticket.