Baton Rouge Cops Said Alton Sterling Tried to Reach for Gun During Altercation: Search Warrant The Dept. of Justice is investigating Alton Sterling's death.

 -- Police officers in Baton Rouge, Louisiana, allegedly saw the butt of a gun in Alton Sterling's pocket and saw him try to reach for the weapon during the altercation that led to his shooting death last week, according to an affidavit for a search warrant filed in the case.

Blane Salamoni, a four-year veteran of the Baton Rouge Police Department, and Howie Lake II, a three-year veteran, both white men, were placed on paid administrative leave after their fatal shooting of Sterling, a black man, outside a convenience store July 5. Parts of the shooting were captured on cellphone videos.

According to the affidavit for a search warrant for a surveillance video recorder at the convenience store, "while the officers were attempting to subdue" Sterling, they "observed the butt of a gun in the subject's front pants pocket."

"When the subject attempted to reach for the gun from his pocket the officers fired their police issued duty weapon at the subject to stop the threat," the document reads.

Sterling was shot several times and died at the scene, police said.

The incident began when police were called in reference to a complaint of a black man who had threatened someone with a gun outside the store, according to the affidavit. The officers saw Sterling outside the store "fitting the description of the person with the gun," the affidavit reads.

The officers said they told Sterling to put his hands on the hood of a car, but Sterling did not comply with the officers' commands or the officers' attempt to restrain him, the document says, and the officers "deployed their BRPD issued tasers." After the officers allegedly saw Sterling reach for the gun, they fired at him.

The document says detectives need to examine the surveillance video recording to further the investigation.

The Baton Rouge Police Department declined to comment to ABC News on the search warrant.

East Baton Rouge District Attorney Hillar Moore III has recused himself from the investigation, he said Monday, citing a professional relationship with Salamoni's parents, both high-ranking police officers.

Moore said last week that when Salamoni and Lake were interviewed by case detectives, the two officers "indicated that they feared for their life and that deadly force was necessary and justified."

The investigation into Sterling's shooting is being led by the U.S. Department of Justice's Civil Rights Division.

Quinyetta McMillon, the mother of Sterling’s son Cameron, called Sterling's death "murder."

"The individuals involved in his murder took away a man with children who depended upon their daddy on a daily basis," she said, adding that he "simply tried to earn a living to take care of his children."

The owner of the convenience store, Abdullah Muflahi, who was an eyewitness to the shooting and recorded it on his cellphone, claims in a lawsuit that immediately after the shooting, Salamoni came inside his store without a warrant and "confiscated the entire store security system.”

Muflahi claims he was illegally detained for hours after the shooting and that police kept his cellphone from him. The Baton Rouge Police Department and the city declined to comment, citing the pending litigation.