For a long time I've refrained from commenting on this topic, since I figured it was possible that the high-profile deaths from these devices might be outweighed by a reduction in shooting deaths. It seems not though:
The Taser stun gun has been advertised and sold as a police tool that can decrease the number of suspect shooting deaths and officer injuries, but a new study suggests its use does not reduce the number of people who die in custody.
The study was conducted by researchers at the University of California San Francisco. They surveyed U.S. city police departments for cases of in-custody sudden deaths in the absence of lethal force in the five years before they started using Taser stun guns and the same period after deployment began. Fifty of the 84 departments approached were able to provide data.
The research group found a sharp increase in the rate of in-custody sudden death in the first full year of Taser deployment compared with the average rate in the five years before the stun guns were used.
"A little bit to our surprise we found a statistically significant six-fold increase in the in-custody sudden death rate in the first full year of Taser deployment, and that rate then declined down near baseline in years two to five," said one of the researchers, cardiologist Zian Tseng.
From the CBC. So it's increasingly apparent that these things don't save lives. I suppose one could argue that the study does not take into account police deaths, but I have a sneaking suspicion that even if they did we wouldn't see much difference.