A 32-year-old woman has pleaded guilty in the shocking death of a Calgary senior nearly three years ago.

Wai Ho Tam, 79, was resting on a bus bench on Macleod Trail near 58 Avenue in July 2010 when he was approached by a woman who then knocked the hat off his head.

When Tam stood up to retrieve the cap, the woman pushed him to the ground.

Tam hit his head on the sidewalk and spent eight months in hospital before succumbing to his injuries in March of 2011.

Marie Monique Lapratt was charged with aggravated assault which was upgraded to manslaughter.

Lapratt pleaded guilty to manslaughter in a Calgary court on Tuesday.

She was sentenced to two years but will only spend about four months in jail because of credit for timed served in pre-trial custody.

(With files from Elissa Carpenter)