A West Texas sheriff's deputy was critically wounded Friday after being shot multiple times during a traffic stop, but authorities credited the body armor with saving his life.

El Paso County Sheriff's Office spokesman Robert Flores identified the wounded deputy as Peter Herrera. He was shot around 1:50 a.m. Friday after he stopped a vehicle in San Elizario, southeast of El Paso along the U.S.-Mexico border. A man in the vehicle started shooting at Herrera after the deputy asked the driver to step out of the car, authorities said.

Herrera did not return fire, Flores said, and the shooter fled on foot along with a female passenger. Deputies found the pair hiding in a tool shed a few blocks away from where the deputy was shot, Flores said.

"Thankfully he was wearing a vest," Flores said. "The rounds that actually struck some of the more vital areas of his upper body were stopped by the vest."

One round did strike Herrera in the upper thigh and another grazed his head, Flores said. Herrera was listed in critical but stable condition after undergoing surgery and was recovering in an area hospital.

The suspected gunman, Facundo Chavez, 27, was booked into the El Paso County Jail without bond on attempted capital murder of a peace officer and other charges. Online jail records list no attorney for Chavez.

Flores said investigators were trying to clarify the "complicated" relationship between the shooting suspect and the woman who was in the car. The woman cooperated with law enforcement and was released from custody, authorities said.

Car trouble played a role in helping deputies track down the shooting suspect, Flores said.

"The vehicle, it stalled out on him," the spokesman said. "It definitely helped us solve this crime."

Dozens of fellow deputies and other law enforcement officers from the El Paso Police Department and the Texas Department of Public Safety lined up in the sheriff office's parking lot to donate blood and plasma Friday during a drive held to benefit Herrera, who has been a deputy for five years.

"We're brothers," said Detective Alan Gurtler, a 30-year veteran of the sheriff's office who was preparing to donate plasma in a mobile blood drive bus. "(An) incident like this with a deputy getting shot multiple times in serious condition, it's very rare here."