For Slain Texas Deputy, Law Enforcement Was 'His Calling,' Brother-in-Law Says

— -- For deputy Darren Goforth, who was shot and killed at a Texas gas station Friday, law enforcement was "his calling," his brother-in-law told ABC News.

Goforth, a Harris County Sheriff's deputy, was filling up his patrol car at a gas station near Houston when a man approached him from behind and shot him several times, according to the Harris County Sheriff's Office. Goforth, 47, died at the gas station.

Harris County Sheriff Ron Hickman announced this afternoon that a man was in custody and facing a capital murder charge in connection with the deadly shooting. The suspect was identified as Shannon Miles, 30, who has a previous criminal history including resisting arrest and disorderly conduct with a firearm, Hickman said.

The motive has not been determined, Hickman said, adding that the shooting appeared to be unprovoked.

A 10-year veteran of the department, he became a police officer in his 30s, brother-in-law Stephen Allison told ABC News today.

"He wanted to spend his whole life in it once he got in it," Allison, 46, said. "He really felt the brotherhood in the community ... that's what he loved to do.

"He was kind of born for it," Allison said.

Goforth is survived by his wife, Kathleen, who works as a school teacher, and two children, ages 12 and 5, Allison said.

"My husband was an incredibly intricate blend of toughness and gentility," Kathleen Goforth said in a statement. "He was loyal...fiercely so. And he was ethical; the right thing to do is what guided his internal compass.

"I admired his quality, perhaps, the most. For that made Darren good. And he was good. So, if people want to know what kind of man he was...This is it. He was who you wanted for a friend, a colleague, and a neighbor."

She added, "However, it was I who was blessed so richly that I had the privilege of calling him my husband and my best friend."

"He was the rock in that family," Allison told ABC News through tears. "The kids loved him."

"I didn't have a brother... when they got together he was like the only other brother in my family," Allison said.

Goforth "never got mad at anybody," Allison said. "He was just a giving individual."

"It was just something that you don't expect to ever happen," Allison said.