LAFAYETTE, Ind. — A Lafayette police officer was shot accidentally after fleeing an aggressive dog during an investigation at a North Ninth Street apartment.

Officer Lane Butler entered the apartment with two other officers while investigating a criminal mischief complaint at an apartment at 813 N. Ninth St., between Salem and Union streets, at 10:45 a.m. Tuesday.

During the course of the investigation the officers learned that a subject wanted on a warrant was possibly residing or visiting the apartment. The Lafayette Police Department reported that the Ninth Street homeowner was cooperative and allowed officers to search the apartment for the subject.

Officers were informed that the homeowner owned a large dog but it was confined in a cage, Chief of Police Patrick Flannelly said.

As officers began to search the apartment, the dog, believed to be a Cane Corso mix, broke out of the cage. Cane Corsos often weigh more than 100 pounds and resemble an English Mastiff.

Officers fled the apartment as to not interact with the animal.

As they went through the door, a round was discharged from one of the officer's firearms, Flannelly said.

The round hit Butler in the back above her protective vest. She was taken to Franciscan Health St. Elizabeth Hospital and is in serious but stable condition.

Update:LPD releases body camera footage from Tuesday's shooting, rules it accidental

“There’s a lot of unpredictable variables as a police officer when you’re out patrolling and replying to calls,” Lt. Brian Phillips said. “You never know what you’re going to encounter.”

The name of the officer whose gun fired has not been made public. An internal investigation is ongoing and the early stages are expected to be done by Wednesday morning, according to the press release.

Once the investigation is completed, a shooting review board will assess all circumstances and will review body camera footage. The review will take place Thursday, according to the press release.

Officers remained on the scene and closed entrances to North Ninth Street between Salem and Union streets for nearly three hours.

Meanwhile, it was business as usual next door at Reliable Parts. Employees said they did not hear any gunshots.

Manager Kevin Isbell said they were unaware any incident was happening until they saw police cars racing into the appliance store’s parking lot and the surrounding area.

Animal Control was also called to the scene to remove the dog as the investigation unfolded. Officers brought the dog, named Libra, to the Almost Home Humane Society.

The dog was examined by the veterinarian staff at the humane society before being returned to its owner, Animal Control officer Derek Bottorff said.

Flannelly praised Butler for "demonstrating tremendous courage and strength" in her recovery.

Butler joined the Lafayette Police Department in January 2015, according to J&C archives. She graduated from Indiana Creek High School in Trafalgar.

She began attending Purdue University then graduated from Ivy Tech Community College with an associate degree in business administration. She has management experience in the private sector.

Officers being shot while on duty is a rare occurrence, Sgt. Matt Gard said. The last instance in LPD history was in 1996 when a suspect shot Officer Jeff Clark.

Clark was hit in the chest after responding to a hit-and-run accident. according to Journal & Courier archives. The suspect was reported as "a homeless man known to police" who continued to charge Clark even after the officer returned fire. The suspect was eventually stopped by a second officer who shot him in the arm, leg and groin.

Prior to this, an officer was shot by a suspect during an early morning car chase in 1993. Officer John Wells was hit in his calf after pursuing what investigators suspected was a father-son team who had robbed 34 banks throughout the Midwest, according to Journal & Courier archives.

Contact Journal & Courier reporter Lindsay Moore at 765-420-5205, lrmoore@jconline.com and follow her on Twitter: @_lindsaymoore.