Updated

A Dallas police officer died Wednesday, a day after he was shot responding to an incident at a Home Depot, the city's mayor said.

Officer Rogelio Santander died at a hospital around 8 a.m., Mayor Mike Rawlings announced at a city council meeting. Santander had worked for the city’s northeast division for three years, police said.

Officer Crystal Almeida was still in critical condition, Dallas police Chief Rene Hall said. A loss-prevention officer, identified by Hall as Scott Painter, was also critical. Hall said they were making a remarkable recovery.

Santander was the second officer nationwide to die Wednesday; a Maine sheriff's deputy was shot overnight by a gunman who stole the officer's car and then robbed a convenience store.

The suspected gunman, 29-year-old Armando Juarez, was arrested after a five-hour manhunt that involved a high-speed chase through downtown Dallas, FOX4 News reported.

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Armando Juarez has been identified as a person of interest in the shootings of two Dallas police officers. (Dallas Police Department)

Juarez faces multiple counts of aggravated assault on a police officer. He was originally sought by police on a felony arrest warrant, authorities said.

The two officers who arrived at the scene were responding to a call from an off-duty officer working at the Home Depot who called for assistance for an arrest, Hall said. The two officers were shot shortly after arriving.

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Dallas Police look for a suspect in the shooting of two police officers. (Ron Baselice/The Dallas Morning News via AP)

"We were just checking out people until we started hearing people like 'There's a shooting. They're shooting,'" witness Mercedes Goledo told FOX4. "From there, they were just telling us to get out of the building. Get out the building. But then they found out that he had went outside."

In 2016, four Dallas police officers and a transit officer were shot dead by a sniper in an ambush attack carried out during a protest over the police killings of black men in other cities.

Fox News’ Elizabeth Zwirz and the Associated Press contributed to this report.