Roger Antony died after being tasered in a town in North Carolina. Antony 61 disabled and with a hearing impairment was riding down the street on his bicycle. Antony is a well known character in the locality having been given the nickname Rabbit because he had large ears.
The constable who tasered Antony had received a call that a man had injured himself in a parking lot after falling off his bicycle. The officer went to the scene but Antony had already resumed riding his bicycle down the street. The constable followed him in his vehicle with his siren on. Antony was ordered to pull over.
Antony failed to respond. The constable then got out of the car and yelled at him to stop. When he again did not respond, the officer tasered him. Antony was then taken to a hospital. He was declare brain dead but put on life support. Life support was later removed. For more see this Gawker article.
Taser International has always maintained that tasers are safe if used properly. When deaths have happened they explain that the tasers themselves are not responsible for the deaths. Critics point out that much of the research on the safety of tasers has been done by researchers partly funded by or having connections with the company. See this entry in Wikipedia for more on safety of tasers. The issue of taser safety has been investigated several times in Canada. See this article.