The family of a man who was fatally shot by his police officer neighbor has filed a wrongful death lawsuit alleging the off-duty officer used excessive force when he shot the man, who was behaving erratically after recently undergoing brain surgery.

Channing Lamar Spivey, 34, was undergoing cancer treatments and had survived a brain surgery less than three months before his May 27 encounter with his neighbor, Luverne Assistant Police Chief Mason Adcock, Al.com reported Sunday, citing a federal lawsuit recently filed on behalf of Spivey’s family members.

Authorities were sent to the home after Spivey’s brother’s girlfriend called 911 to report Spivey was growing agitated, according to the lawsuit. She mentioned his recent brain surgery to dispatchers during the call.

Spivey was uncooperative and broke an ambulance window with his fist when the responders, along with a sheriff’s deputy, arrived at the home, the lawsuit said.

The deputy tried using a stun gun to subdue Spivey, but Spivey continued to walk toward the deputy and ignored orders to get on the ground, the suit alleged. The deputy then drew his gun and Spivey’s brother’s girlfriend ran to Adcock’s home, about 100 yards (91 meters) away, for assistance.

She told Adcock that Spivey was behaving erratically after having brain surgery, according to the lawsuit, which says she went to Adcock’s home because she knew he was a police officer and thought he could help deescalate the situation.

Adcock joined the deputy and the men pointed their guns at Spivey, who had approached Adcock’s home and was now in his driveway, according to the lawsuit.

Spivey’s brother again told the officers that Spivey was recovering from brain surgery and asked them not to shoot, according to the lawsuit.

When Spivey took a step toward the officers, Adcock fired his gun at least seven times, killing Spivey, according to the lawsuit.

Griffin Sikes, the Montgomery attorney who filed the lawsuit on behalf of the family, said Spivey was unarmed at the time and questioned why Adcock had to use his weapon.

The Alabama Law Enforcement Agency is investigating the shooting. The agency referred Al.com to its initial statement on the shooting, which did not name Adcock or Spivey, the news outlet said.

Adcock remains on active duty with the Luverne Police Department. He declined to comment to Al.com, citing the state investigation and the lawsuit.