A dog was shot dead after a police officer knocked on a door to inform a resident they had left a car door open door. Courtesy WPLG Ten News

IT’S enough to make anyone’s blood curdle. A Florida family has been left utterly distraught after their beloved rescue bulldog-cross Duchess was shot dead by a policeman.

The two-year-old canine had run up to answer the door after an officer knocked to inform the owner, Gillian Palacios, that she had left her car door open, WPLG reports.

Ms Palacios then watched in horror as the cop’s immediate reaction was to draw his gun and shoot the young dog in the head — not once, but three times.

A surveillance camera captured the shocking incident. Ms Palacios is seen briefly reaching out to try to pull back her dog but she was simply not given any time to intervene.

Images also show Ms Palacios and her daughter drop into uncontrollable sobs.

A distressed Ms Palacios said the officer told her the dog charged at her and left saying Animal Services would pick up the bloodied corpse.

“She was curious. She wasn’t barking (and) she wasn’t growling,” she said. “There was no reason for him to think she was aggressive in any way.”

“There were a million things he could have done other than shoot her three times in the head,” Palacios said.

The Palacios family fosters and rescues dogs in the area, and Ms Palacios is listed as a pet sitter and bookkeeper on LinkedIn.

Duchess was adopted from a local animal shelter and was said to be loving and docile.

Florida City police spokesman Officer Ken Armenteros confirmed that one of the department’s officers shot a dog on Tuesday, and said the police department is “gathering all the facts at this time”.

“We don’t have the luxury of hindsight,” Armenteros said. “We have to use the information that is given to us in a split second. So, the officer has to make that decision with the information that he has available.”

The officer has been placed on administrative leave while an investigation into the shooting is underway. The Palacios family is also considering legal action.