A former Air Force colleague of the Texas church shooter says that the gunman told her he bought pets to use as target practice, and that the Dylann Roof church massacre was “cool.”

Devin Kelley, the gunman responsible for Sunday’s deadly mass shooting at a church in Sutherland Springs, reportedly told his Holloman Air Force Base colleague Jessika Edwards that he bought dogs from Craigslist just to kill them, CNN reports. Edwards says she worked with Kelley at Holloman Air Force Base in New Mexico between 2010 and 2012.

The two reportedly reconnected in civilian life in 2014 on Facebook, and that’s when Kelley allegedly told her that he “was using the dogs as target practice.”

READ more: Devin Patrick Kelley: Texas church shooting suspect had history of animal cruelty

She also said that while the two were stationed in New Mexico, he seemed to have an obsession with mass murder, and would often make jokes about it.

“He would make jokes about wanting to kill somebody. And we would say, ‘wait, that’s not funny.'”

Edwards even told her superiors to “back off or he would shoot the place up” when Kelley was disciplined, which, she said, was often.

“He was always getting into trouble. It was problem after problem.”

Kelley was court-martialed in 2012 for assaulting his wife and step-son, something that Edwards said had a large impact on his work performance and behavior.

Edwards, a staff sergeant who supervised Kelley, said he “threatened to kill himself one time if [she] didn’t let him go see a chaplain.”

Air Force officials confirmed that Edwards and Kelley worked on the base at the same time, but wouldn’t confirm if the two worked together.

Edwards said that when Kelley connected with her on Facebook after serving time for the assault charges, he would say things that made her uncomfortable, enough to eventually block him.

At one point, Kelley brought up Dylann Roof, the South Carolina church shooter.

“He would say ‘isn’t it cool? Did you watch the news?’ He would say he wished he had the nerve to do it, but all he would be able to do is kill animals.”

Edwards said that she cut off communication with Kelley, but didn’t think he’d actually act on his words.

“In a sane person’s mind, when people say something like that you don’t think it’s something they’re going to do.”

After the shooting, Edwards got a text from a friend that said Kelley was the shooter. She said it upset her so much she dropped the glass she was holding and started to cry.

READ more:Dozens killed at mass shooting inside Texas church

When she cut him off on Facebook, she gave him her phone number and told him that if he “found himself in a state of mind that he was going to hurt himself or someone else, to call me.” He never did.

“It’s upsetting because you feel like we failed. But in reality we did everything we possibly could do.”