BATON ROUGE - Information is slowly emerging about the man behind Sunday mornings shooting on Airline Highway that left three officers dead and injured another three.

Officials identified the gunman as a 29-year-old black man named Gavin Eugene Long. Long's address was listed in Kansas City, Missouri.

Long was killed by officers in the firefight that happened when he came into contact with law enforcement officers at a car wash on Airline Highway near Old Hammond Highway. A witness reported seeing Long, dressed in all black and wearing a mask while carrying a rifle in the Airline/Goodwood area.

ABC News reports that Long is listed as a former Marine in public records. He’s listed to have started duty in August 2005 until his discharge as an E-5 level sergeant in August 2010. Long had been deployed to Iraq from June 2008 to January 2009, according to WSJ.com.

Records have also revealed that the man carried out the attack that killed three and injured three more on his birthday.

The Wall Street Journal connected the attack to an anti-government group known as the New Freedom Group.

Heavy.com looked into court records and found that Long filed for divorce from his wife in 2011 in a Kansas City court. It’s unknown if Long had children with his wife.

The University of Alabama’s website also found that Long was a Dean’s List student at the school in 2012, but Heavy journalists found out that he was a student there for just one semester. The Associated Press reported that campus police had no interactions with Long during his time at the school.

Two other suspects were arrested in Addis in connection with the shooting after a witness spotted them entering the Port Allen Walmart to change out of suspicious-looking black clothing. The men were brought to BRPD VCU for questioning in connection with the shooting.

Police have said they believe Long was the lone attacker in the incident. LSP's Col. Mike Edmonson said in an afternoon press conference that the shooting scenario is no longer active and that the shooter, Long, has been killed.

Social media accounts for the killer were tracked by journalists and linked on Twitter after it was discovered he went by the online alias "Cosmo Setepenra." In his Instagram and Twitter posts, Long espoused anti-police views and even praised the Dallas attacks in one post.