I remember a case from years ago, where an unarmed and handcuffed man was tasered to death in Canada.
Constable Millington tasered Dziekański. He began to convulse and was tasered several more times after falling to the ground, where the four officers pinned, handcuffed, and continued to taser him. One eyewitness, who recorded the incident on her cellphone, told CBC News that Dziekański had been tasered four times. "The third and fourth ones were at the same time" delivered by the officers at Dziekański's right and left, just before Dziekański fell.[12][16] According to B.C. Crown counsel spokesman Stan Lowe, Dziekański was tasered a total of five times.[3] Constable Millington testified that he deployed the Taser four times, but he believed that in some of those instances the probes may not have contacted Dziekański's body.[17] Dziekański writhed and screamed before he stopped moving. Cpl. Benjamin Monty Robinson stated he then checked for a pulse, but his heart had stopped. Testimony from the other RCMP officers state they never saw anyone including Robinson check for a pulse.[18] Dziekański did not receive CPR until paramedics arrived on the scene approximately 15 minutes later. They were unable to revive him and pronounced him dead at the scene.
http://en.wikipedia.org/wiki/Robert_Dzieka%C5%84ski_Taser_incident