I occasionally get news feed articles about these. I'm going to start collating them here. It's sort of the opposite of the Busted Teachers thread.
Woman, 53, Uses Martial Arts To Nab Alleged Burglar
Lighthouse Point Black Belt Chases, Holds Burglar For Police
POSTED: 6:10 pm EST January 19, 2008

LIGHTHOUSE POINT, Fla. -- A Lighthouse Point woman used her skills in martial arts to tackle an alleged burglar after she chased him six blocks.

Margot Foster, 53, arrived home at 2600 block of Northeast Court Friday around 10 a.m. and found a man identified as Gregory St. Germain, 24, ransacking her house, police said. She was able to tackle the suspect outside of her home, but police said he was able to get free.

The marathon runner and black belt in martial arts then chased St. Germain for six or seven blocks until she caught up with him and held him until police arrived, according to patrol Sgt. Alan Nestor of the Lighthouse Point police.