Tyaina Finch later changed her story and claimed she used her gun against him in self-defence.
A 27 year old, Tyaina Finch, told Philadelphia police that her dog shot her boyfriend accidentally as she tried to wrestle it from the pet's mouth.
She later changed her story and claimed she used her gun against him in self-defence.
Mark Hudson, 26, was killed in his home in Philadelphia during the incident, Daily Star reports.
Authorities say he was trying to break up with Finch at the time.
Hudson – who worked as a police offer for four years – was pronounced dead at the scene. District Attorney Jack Whelan described Finch's version of events as "inconsistent".
He described the couple's relationship as "tumultuous" and said officers had been called to the home previously over domestic disturbances.
He said: "We believe she acted on this particular day with specific intent to kill."
His family were said to be touched by the service which police and firefighters attended – Hudson began his career as a volunteer fireman when he was just 16.
"We just lost a great, great person, he was a good, good guy," said one relative.