Video of a Texas police officer fatally shooting a tail-wagging pit bull puppy has gone viral, provoking death threats against the officer and outrage at authorities in the Dallas-area city of Cleburne.

The video, apparently first posted to Facebook on Oct. 16, has prompted an expanded investigation into the Aug. 10 shooting, along with calls for the officer’s firing.

The owner of the dog that was killed, a 6-month-old pit bull named Maximus, requested a copy of the video after the shooting. It’s not clear how the video got released on social media.

Taken by the officer’s lapel camera, the video shows the officer making what sound like kissing noises to Maximus, who appears to be wagging his tail. Then, three shots rings out.

“Why?  I just don’t understand why,” dog owner Amanda Henderson told KTLA sister station KDAF.

Every shot makes her cringe, she said of the 22-second video.

In two statements, the city of Cleburne  has said that the incident is under investigation. The officer involved is on paid administrative leave and has received death threats, according to the city, which has about 30,000 residents and is about 50 miles southwest of Dallas.

“The short video does not tell the whole story,” the city stated.

The officer was responding to a 911 call in which residents reported three loose dogs had trapped them in a vehicle, according to the city’s account. One dog was immediately found, but two others remained loose, the city stated.

“The officer was attempting to secure the other dogs until animal control arrived when one dog became aggressive,” the city’s first statement, released Oct. 17, said.

A lapel-cam video taken before the shooting shows the officer petting the first dog, later identified as Dough Boy, which bounds up to him on a residential street. The officer then approaches a house to find out if the resident recognizes the black-and-white dog.

“Watch yourself. Somebody said this one was aggressive. I have’t seen it, but …” the officer told the resident.

Minutes later, Maximus was dead.

No video has been posted showing what occurred between the officer’s encounter with Dough Boy and the shooting of Maximus, but the officer’s police report was released to the local Cleburne Times-Review.

After driving around, the officer, identified as Kevin Dupre, found the other two dogs nearby in a grassy area between homes. They didn’t seem aggressive at first, but then one began growling when the animals got within 20 feet of the officer, the report states.

“I made kissing noises in an attempt to calm the dogs,” the report states. “I raised my duty weapon to the ready position pointed at the growling dog’s head. As soon as I lifted my pistol, the dog began coming up the hill, continuing to growl and display its teeth. The other dog began backing away. I fired three shots at it. It rolled back into the ditch and died.”

A Facebook page called Justice 4 Maximus states that the Henderson family’s three dogs got out while the family was out shopping. When the Hendersons returned home, a neighbor told them a police officer had shot one of their pets — Maximus — and placed another — Coco — in the pound.

A third lapel-cam video from the shooting’s aftermath shows a responding animal control officer easily collecting Coco while the body of Maximus lies in the ditch.

After the shooting video spread online — shared by animal advocates, police critics and others — the city released a second statement on Monday, saying an administrative review of the incident was expanding “as new information becomes available.” The Police Department’s policy on the handling of aggressive animals in future was also being examined.

The Texas Rangers had been asked to conduct an independent investigation by the city’s mayor.

“While the video is very disturbing, we need to honor the process and complete reviews,” said Mayor Scott Cain.

Death threats against the officer were being taken seriously, Cain said.

An online petition to “terminate” Dupre had garnered more than 59,000 signatures by Tuesday.