Commerce City Police Chief Chuck Saunier said Monday he has ordered a full investigation into the circumstances that lead to a police officer shooting a pet dog that was being restrained by an animal control officer when it was killed.

Video of the dog’s death on Saturday was captured by a neighbor and posted on social media, raising questions about the incident and anger from pet lovers. In a statement Monday afternoon, police identified 3-year-old Chloe as a pit bull and characterized it as vicious.

“Obviously, this kind of force is a last resort for our officers,” Saunier said. “It truly is a tragedy any time a member of our department has to use their weapon to ensure community safety. Our initial review of this incident indicates that the officers responded appropriately to the 911 call and used the force necessary to protect the public.”

Saunier continued, “The home video is disturbing, however until the investigation is complete, it is inappropriate to speculate on the incident because we don’t have all of the facts.”

A relative of the owner who was keeping the dog at the home faces numerous violations, police said, including possession of a vicious animal and violation of the city’s pit-bull ban. The owner nor the relative keeping the dog have been named by police.

Police said the officer looked for someone responsible for the dog for 20 minutes, and though the animal control officer had a catch pole noose around the dog, it remained agitated and uncontrolled.

“For the safety of the community and the officers on scene, the officer fired his weapon multiple times to put down the dog and ensure the safety of everyone,” police said.

Dog owner Christie Mueller, 34, of Westminster disagreed.

“It was completely unnecessary,” she said. “It never should have happened — it should have been handled differently,” she said.

Through social networking Mueller planned a vigil and protest Monday at 7 p.m. at the Commerce City Civic Center, 7887 E. 60th Ave.

“Something has to be done,” Mueller said. “You can’t get angry and ignore it.”

Mueller hopes the event prompts police and other city officials to seek discipline against the officer and improve training on dealing with unattended dogs.

In a press release, the Commerce City police urged the public not to rush to judgment.

“In 2010, the police department was involved in another shooting involving a vicious dog,” the department said. “That incident also was portrayed poorly by the media, although a jury later determined the officers’ actions were justified.

” Since that incident, all members of the Commerce City Police Department, including the officers on scene of this incident, attended mandatory training on dog encounters. This training included how to approach dogs and how to read their behavior.”

Police said the dog was being kept at the home.

Kieran Nicholson: 303-954-1822, knicholson@denverpost.com or twitter.com/kierannicholson