A 56-year old grandmother is being hailed as a heroic Good Samaritan who saved the life of a police officer.

"I did what God needed me to do," said Vickie Williams-Tillman, a petite woman standing just 5'2", who jumped on the back of a hulking crime suspect who was pummelling a police officer and was grappling for the latter's firearm, reports said.

Williams-Tillman was driving early Sunday morning, Feb. 21, in Baton Rouge, Louisiana when she saw an officer on the side of the road confronting a suspect, People reported.

She then saw the suspect attack the officer. She quickly dialed 911 to call for help, but then felt that she could do more than that to help.

"I thought, 'They're not going to make it in time.' There was just a small amount of time before something could have happened," said the mother of three who works at a Catholic school during the day and cleans offices at night.

Cpl. Billy Aime, the 44-year-old police officer rescued by Williams-Tillman, had earlier found drugs in the suspect's vehicle during a traffic stop and was handcuffing the suspect, identified as 28-year-old Thomas Bennett, when the latter grabbed the officer's baton and used it to him in the head, according to Baton Rouge Police.

That's when Williams-Tillman sprang into action. Risking her own safety, she "jumped out of her vehicle and onto back of the assailant," according to police.

"It was just instinct," she said, adding, "God led the way."

"They both had their hands on the gun to see who would get it first, so I twisted the suspect's arm," she said. "Then we were all falling. I didn't let go of his arm until we all fell."

The backup police unit then arrived and subdued Bennett with a stun gun.

Williams-Tillman hurt her hand and wrist and was taken to the hospital where she was treated.

A day after the incident, the Baton Rouge Police Department thanked Williams-Tillman on its Facebook page while Mayor-President Sharon Weston-Broome held a special press conference honouring her.

"Vickie Williams-Tillman epitomises the true Good Samaritan," Weston-Broome said in a statement, The Advocate reported.

"She reached out and offered a courageous and unconditional response to the officer. Ms. Williams-Tillman is a hero and demonstrates the true meaning of loving God and loving your neighbour," she added.

Aime, the officer Williams-Tillman saved, embraced his rescuer, saying, "This is a true hero right here that saved my life."