(CNN) A man "believed to be the alleged gunman" in the killing of a uniformed Houston-area sheriff's deputy was in custody and being questioned Saturday morning, Sgt. William Kennard of the Texas Department of Public Safety told CNN.
No charges have been filed against the man, Kennard said. The man's name wasn't given.
It was the man's mother who called the Harris County Sheriff's Department about her son, Kennard said. "All the information she had heard led to him."
A red pickup truck was parked at the spot where deputies took the person in custody, according to video shot by CNN affiliate KTRK. Authorities had said the suspect drove away from the shooting in a red Ford Ranger.
'Execution-style' killing
The suspect shot Deputy Darren H. Goforth, 47, while the deputy was filling up his patrol car at a Chevron station just after 8:30 p.m. (9:30 p.m. ET), Harris County Sheriff Ron Hickman said.
"Deputy Goforth was refueling his vehicle and returning to his car from inside the convenience store when, unprovoked, a man walked up behind him and literally shot him to death."
Goforth was shot multiple times from behind and then fell to the ground, where the suspect shot the deputy multiple times again, said Deputy Thomas Gilliland, a spokesman for the sheriff's office.
Goforth, a 10-year veteran of the Harris County Sheriff's Office, died at the scene.
The shooting appeared to be "an unprovoked, execution-style killing," Hickman said.
"I have been in law enforcement (for) 45 years," the sheriff said. "I don't recall another incident this cold-blooded and cowardly."
'He did not say anything'
The gunman gave no indication of his motive. He drove away after the shooting in a red Ford Ranger, authorities said.
"He (the suspect) did not say anything," Gilliland said.
Surveillance video from the gas station captured an image of the suspect.
Authorities urged any witnesses in the area to come forward, saying some bystanders called 911 to report the shooting.
About 30 minutes before the shooting, Goforth had investigated an accident, but authorities said it's unclear whether there was a connection to the attack.
A husband and father
Goforth leaves behind a wife and two children.
"Our hearts go out to them," Hickman said, asking the community to remember his family in prayer.
"In times like these, it's important to ask for the prayers from this community," he said. " ... It strikes us in the heart to simply be a target because you wear a badge."
Hickman vowed the suspect will be held accountable.
"We will hunt this person down and do our best to bring this person to justice," he said.
After the news conference, he led a group of law enforcement officials in prayer, their heads bowed solemnly.
Harris County District Attorney Devon Anderson called the killing "horrifying."
"It's an act of cowardice and brutality the likes of which I've never seen before," she said.
Leading causes of officer deaths
Including the attack Friday, 23 law enforcement officers have been shot to death so far this year nationwide, according to the Officer Down Memorial Page.
Traffic incidents are the leading cause of officer fatalities in the U.S., followed by shootings.
