As you might imagine, the former police officer who fired three shots into the back of a minvan full of children has some regrets.

"My heart sank when they finally stopped and I was at the passenger side at that time seeing them get out at gunpoint again," Elias Montoya told ABC News. "I couldn't believe it that there were that many children in there."

In October, Oriana Farrell was driving her five children—aged 6-16—when she was pulled over for speeding. She fled the scene and was pulled over a second time by the same officer. Farrell's 14-year-old son confronted the officer before running back to the van after the officer pulled out a Taser. Then the whole family locked themselves in the van.

Montoya arrived on the scene not long after, as backup, and, according to him, was not informed that the van was full of kids. "I'm approaching the van on the left-hand side," he said. "All I see is silhouettes of heads. A bunch of silhouettes of heads and what went through my mind is that we're outnumbered."

As another officer smashed in the van's tinted windows, Farrell attempted to drive off again, at which point Montoya fired three shots at the back of the van. "I'm not shooting at a human being. I'm shooting at a tire," Montoya said.

"If I knew that there was even one child in that vehicle. I wouldn't have done it," he said, adding that he bought the family McDonald's as they were being booked.

Farrell was charged with child abuse, fleeing the scene, and misdemeanor possession of drug paraphernalia.

Montoya was terminated from the New Mexico police department in December.