A Hawkesbury man has been found guilty in the sexual assault and killing of an 81-year-old woman eight years ago.

Violet Graves was found strangled in her Hawkesbury apartment in July 2000.

Robert Brunet, 63, started his testimony this week but the trial ended abruptly with his admission of guilt on Tuesday.

Instead of continuing with the trial, Brunet told his lawyers he wanted to plead guilty to a second-degree murder charge.