The Taser has become a tool more law enforcement agencies have come to rely on. Every time an officer pulls the trigger, 50,000 volts are injected into the target. Advocates say it's a safe way to subdue a suspect, but UCSF researchers, have their doubts.
"In our opinion, there is a potential lethal risk with Tasers," said Zian Tseng, MD, a UCSF researcher.
Cardiologists Byron Lee and Zian Tseng studied data provided by law enforcement agencies from 50 cities, and found the number of in-custody deaths went up six-fold in the first year a department started using Tasers. Lee and Tseng believe officers may be aiming too close to the heart.
"The Taser shoots pulses several times per second. Those pulses can actually overtake the heart and cause a heart rate that's 250 to 300 beats per minutes," said Tseng.
Many law enforcement agencies in the Bay Area use Tasers including Oakland Police, but the department says it has never had any Taser-related deaths.
"I think our training is pretty superior here at the Oakland Police Department," said Lt. Jeff Thomason, an Oakland Police Department spokesperson.
Jeff Thomason of Oakland Police says officers in his department must take a 10 hour class before using a Taser, as well as an annual four-hour review. Oakland Police officers also call for an ambulance every time they Tase a suspect just to be safe.
"It's a great standoff weapon for us. It causes our officers not to engage violent hostile suspects out on the street. And it has limited our number of injuries to officers and to suspects," said Lt. Thomason.
Even so, UCSF researchers say based on their study, it might be time for all law enforcement agencies to review their Taser policy, how they use them, and whether or not they need them at all.
"We think more research needs to be done to make sure we're not doing anything to harm the public," said Bryon Lee, MD, a UCSF researcher.
Researchers can see their observational study has limitations. Several California cities and all of the largest U.S. cities surveyed were unwilling to release information.
You can read the Taser study from the American Journal of Cardiology. Click here