Sergeant Kimberly Munley recalled today how she had been engaged in the mundane task of washing her patrol car when the call came that was to turn her into a US heroine.

The police officer credited with stopping a gunman at the Fort Hood military base in Texas last week described the confrontation in an interview – her first since the shooting – on the Oprah Winfrey show.

Munley, who had been on traffic duty that day, said she had abandoned her washing chore when a call came through that there was a shooting at the base.

She ran to the scene, which she described as "confusing and chaotic", with 13 people already dead and dozens wounded.

People were pointing at a corner where they thought the gunman was. She ran forward, turned the corner and fired twice.

Munley was hit by three bullets. She described how the first shot felt like "a muscle being torn out of my leg". She underwent two operations, one on a severed artery.

But she was well enough on the evening of the shooting to speak by phone to family and friends. Yesterday she met the US defence secretary, Robert Gates, who visited her in hospital.

Munley, 34, a mother, said she expected her recovery to be slow but she knew she could do it. "I'm doing well," she said.

"Every day is progress for me, and things are getting better day by day. And emotionally, I'm just hoping that the rest of the officers and the injured and the families of the deceased are healing as well."

Although there is still some confusion about which shots brought down the alleged gunman, officials have attributed the bullets that brought him down to Munley.

The commander of the base, Lieutenant-General Bob Cone, said of Munley: "It was an amazing and an aggressive performance by this police officer."

Munley had been trained in tactics for dealing with such a gun incident. As part of that training, she had been told to fire rather than wait for additional back-up, a delay that is blamed for a high casualty toll at the 2007 Virginia Tech shooting.

Also interviewed today was her partner Sergeant Mark Todd, 42, like Munley a civilian police officer, who said it was the first time in his career that he had used his weapon.

Major Nadil Malik Hasan, who is suspected of carrying out the shooting, is also in hospital. He has not yet been charged and is refusing to talk to investigators.

It is alleged that he did not want to be deployed to Afghanistan or Iraq because he did not want to kill fellow Muslims, and that the military would not allow him to leave the services.