The Louisiana police officer who shot and killed a Portland man’s leashed dog last month has resigned, according to a news release from the Sulphur, Louisiana, police department.

An internal affairs investigation into Officer Brian Thierbach’s actions of April 28 found that he violated the Sulphur Police Department’s policies and procedures regarding the use of force, personal conduct and behavior.

Thierbach shot Arzy, a Labrador-Newfoundland-golden retriever mix, in front of his owner, Brandon Carpenter, who was handcuffed on the ground. Carpenter, a 28-year-old itinerant musician, who had hopped a freight train to Sulphur, Louisiana, was found by police that morning after he and traveling companion Logan Laliberte of Auburn climbed into an empty box truck to sleep out of the rain.

The officer told Carpenter that Arzy had nipped his foot, but an independent witness to the events told police that the dog had not attacked Thierbach.

“I am a dog lover and I am deeply saddened by this incident,” Police Chief Louis Coats said in the release issued Thursday afternoon. “I realize there is nothing I can say that would take away the hurt this incident has caused Mr. Brandon Carpenter. The actions of Officer Thierbach did not represent what I expect from the officers of the Sulphur Police Department. Those of us who serve as law enforcement officers do so with the responsibility of serving and protecting the community as professionals. The resignation of Officer Thierbach was accepted so that the officers and community can heal and move forward.”

Thierbach resigned Wednesday, before final disciplinary action could be taken, according to the police department. The Calcasieu Parish Sheriff’s Office is conducting a criminal investigation into this matter.

The incident has attracted attention nationwide, both from the media and on social networking sites like Facebook. A Facebook page called “Justice For Arzy” has attracted more than 8,300 likes and a petition calling for Thierbach’s dismissal on the website has reached more than 7,500 signatures.

Carpenter said Thursday in a phone interview that Thierbach’s resignation is “a couple steps in the right direction.”

“At this point, it’s all I could have hoped for. I do think he should be brought to full justice,” he said. “Now I’m going through some inner turmoil. Can’t I just forgive and forget? I’ve certainly made some mistakes in my life. But nobody’s above the law. I had to pay for my mistakes. That’s why I learned not to do them again.”