A Dallas police officer died by apparent suicide a day after he and three other officers fatally shot a homicide suspect as they tried to arrest him this week, according to a department email obtained by The Dallas Morning News.

The officer who died, Matthew Bacon, was assigned to the U.S. North Texas Fugitive Task Force, which is made up of U.S. Marshals and officers from Dallas and Mesquite. According to internal memos sent by the chief to all officers and obtained by The News, police officials learned of his death around 6 p.m. Tuesday.

Bacon was one of four officers on the task force who opened fire around 10:15 a.m. Monday while trying to apprehend Corey Wayne Thomas in the 3700 block of South Tyler Street, near Marvin D. Love Freeway, police said. The officers fatally shot Thomas, who was suspected in the July 24 killing of 45-year-old Jason Salazar inside a vehicle, Dallas police said.

Bacon had been with Dallas police for 18 years. The department held sessions for officers Wednesday to discuss wellness after the chief informed the department about the officer’s death. Dallas police last year launched a new unit that focuses on improving officers’ mental wellness.

“This is a heartbreaking loss for our DPD family,” Dallas police Chief Eddie García said in one of the memos to officers this week. “As your Chief, I’m asking you to pause for Officer Bacon and his family, and also to check in with yourself.”