An Army veteran was thrown behind bars Tuesday for allegedly tying her PTSD therapy dog to a tree and shooting him five times at close range — killing the poor pup for no apparent reason while a soldier filmed it.

Marinna Rollins, 23, was arrested by police in Fayetteville, NC, and charged with animal cruelty and conspiracy after footage of the deranged incident reportedly surfaced on Facebook.

Court documents obtained by the Fayetteville Observer describe how she teamed up with her boyfriend, Jarren Heng, 25, for the seemingly random killing earlier this month.

The couple allegedly led the white and gray pit bull to a wooded area before tying him to a tree and taking his life. The canine — dubbed Camboui, but referred to as Cam or Cammy — ultimately was shot five times with a rifle as Rollins and Heng, who is still enlisted and stationed at Fort Bragg, took turns filming him.

“Let me hit him once,” Heng can be heard saying in the video.

Throughout the disturbing clip, he and Rollins both laugh and joke about the dog’s brutal death before they eventually dump him in a shallow grave.

“That’s his nerves going,” Rollins says, as Camboui’s body begins to convulse.

She and Heng can also be seen drinking alcohol in several pictures that they took before allegedly killing him.

“It’s been real, Cammy,” Rollins says while burying him. “I love you, you’re my puppy, you’re a good puppy. But…”

It’s unclear if the pair had been putting Camboui out of his misery or whether he was suffering from sort of illness at the time of his death — which took place on April 16 or 17, according to WTVD.

Camboui reportedly was given to Rollins as an emotional support dog after she was diagnosed with post-traumatic stress disorder and other mental health issues.

In April, the Army vet began writing posts on Facebook in an apparent attempt to find the dog a new home.

According to the Observer, she wrote on April 17 that Camboui would be heading to his new owner soon.

“Sad he has to go, but he will be much happier where he is heading off to,” Rollins reportedly said.

“He’s going to have such a great new life,” Heng replied, adding a smiley face emoji to his post.

A Facebook page, titled “Justice For Cam,” has posted the graphic footage of Camboui being killed, in an attempt to bring more attention to the incident.

“A lot of people are getting upset that this video is posted here,” the moderator wrote Monday.

“You do not have to click play and watch it but let me clarify something. Marinna Rollins is trying to claim that the dog was sick and suffering and that she did this out of Mercy. The video has been shared, to prove otherwise, because we don’t want her to get off easy for the crime she committed. This was clearly not mercy.”

An investigation by the Cumberland County Sheriff’s Office and Cumberland County Animal Control ultimately found that Rollins and Heng had both broken the law when they took Cam’s life. It not only turned up the video, but also several text messages in which they allegedly discussed the shooting.

“As graphic as the videos are, they tell Camboui’s story, that he was unable to do,” the moderators of the “Justice For Cam” page said. “Many people thought he was going to a new home, and family. These videos prove otherwise, that he was brought out to a wooded area, shot multiple times, and then beaten and dragged to a shallow grave. Like a piece of trash, not a well taken care of ESA. His body is still out there, somewhere in those NC woods.”

Rollins’ bail initially was set at $10,000 Tuesday, while Heng’s was set at $5,000 after his arrest Monday night. But both amounts were raised to $25,000 following requests from prosecutors.

“They can be heard on the tape laughing and giggling as the dog was being killed,” Cumberland County District Attorney Clark Reaves said Tuesday night during the couple’s first court appearance.

“It was a therapy dog.”

Rollins and Heng have each been charged with animal cruelty and conspiracy. It’s unclear when their next court date is.

With Post wires