Officers responding to a 999 call visited the house of Gale Marmoy on the Isle of Wight and were greeted at the door by her husband, Michael John Gregory.
The 77-year-old was reluctant to let them into the house saying he was in the middle of cooking.
Gale on the night of the attack. The video was featured in an episode of Panorama
Gregory eventually realises he has no choice and allows them in where they find Gale sitting terrified with two black eyes and a swollen face.
She said: "People don't realise how bad these things are but with that footage they could see how bad it was.
"A picture does tell a story but actually watching it, they could see I was totally confused...which you don't get from a photograph.
"The last time he was punching me, I thought ‘this is it’, you’re going to die tonight.
"I was thinking of my children, my grandchildren. He just meant to do me harm, which he did, but I didn’t realise how much harm, I was terrified."
Gregory was jailed for 10 years for the attack.
The video is being used to highlight the usefulness of police body-worn cameras which are being trialled in a number of forces around the country.
Hampshire Constabulary’s Detective Superintendent Ben Snuggs said: "This case provides a graphic insight into the power of Body-Worn Video (BWV) as an independent witness that captures crucial early evidence in an investigation."
Gale certainly agrees convinced that if police hadn't intervened that night "they would have found a body".