In the past week, two men have died in Los Angeles county, after being Tasered by police officers.
The non-lethal stun gun is used by law enforcement agents to subdue suspects, but preserve life.
Doctoral student, Colin Christensen is researching why Tasers can sometimes kill. He joined Take Two from UC Berkeley Law School's Jurisprudence and Social Policy program.
1. The targets physical condition determines the level of risk for fatality
"Physiologically, the concern that most physicians are worried about is cardiovascular syndroms and conditions that police are unaware of when they discharge a taser at a subject. Which is to say, when you introduce 50000 volts of electricity into somebody's body and they have a heart condition, this can cause ventrical fibulation which essentially causes the heart to go into cardiac arrest. This is often why people are killed by tasers."
2. Certain amphetimenes can compound the damage of a taser
"This is something we're seeing in ... least one of the two cases in LA this week, is this conditions called 'excited delirium,' which is when a subject is essentially on some sort of controlled substance and intoxicated with an accelerated heart rate. We're talking about cocaine and amphetamines principally. There's a lot of evidence to suggest when you introduce this electricity into somebody's body who's intoxicated... you have a much higher likelihood of cardiac arrest."
3. The taser hadn't become a commonly used tool until 2000
"Tasers been around for about 30 years, but it doesn't really have any meaningful market penetration until the year 2000. So for instance, by the end of 2001, over 1000 police agencies in the United States had purchased some tasers from Taser International who has the overwhelming market share in this technology. That same year, 25 agencies had purchased a taser for every one of their on duty patrolmen. To put this in perspective, by 2009 that number had increased to 5000 agencies with a taser for every on-duty officer and over 15,000 agencies that had purchased tasers in some capacity just not for every on duty officer."
4. Taser use is up while baton and bean-bag gun use are both down
"I think more than anything it's signaling to us that the taser has an increase prominence in both day to day police encounters and in our national dialogue about policing. It's a tool that does have a lot of virtue about it, but it's not perfect. And it's certainly not a cure all for our on going struggles with police violence in this nation."
5. There's no evidence to suggest its use would have prevented any police killings
"To say that the taser can prevent these killings is just empirically false. There's no data to suggest that the number of police killings has gone down as the introduction of tasers has gone up. In fact the data on national aggregate statistics suggests the exact opposite. But what we need to shift our conversation to is not just [say], 'Okay police officers should have tasers in these circumstances.' It's that they should have tasers and we should be retraining them to approach situations where they're going to use lethal force much differently."
To hear the full conversation, click the blue player above.