Two incidents this week in which police used Tasers to subdue nonviolent suspects have thrust the popular stun gun into the spotlight again and raised new questions about the device's use and potential misuse by law enforcement officials.
Monday, police in California shocked a 15-year-old autistic boy with a Taser. Two days later, during a speech by Sen. John Kerry, D-Mass., at the University of Florida, officers Tasered a 21-year-old student who refused to stop asking the senator questions.
The weapon -- used by some 11,500 police agencies in more than 44 countries, according to its manufacturer, Taser International -- has been criticized by civil rights groups for years. They have questioned Taser's status as a "nonlethal weapon" by pointing to incidents in which people who have been stunned later died.
While neither of the two suspects in this week's incidents died or were seriously injured, the cases have focused attention on the increasing use of Tasers by police and the widely varying ways that use is regulated.
Who can be shocked, under what circumstances, for how long, and how many times varies from state to state and department to department, a fact that critics say allows for abuse. Taser International, which offers no guidelines on use of the weapons, says this allows police agencies to tailor their use according to local guidelines and case-specific needs.
While on the face of it, shocking a 15-year-old autistic boy with 50,000 volts of electricity for "acting suspiciously" but nonviolently might seem over the top, the Orange County (Calif.) Sheriff's Department maintains the device was used for the boy's own good.
"The use of the Taser was definitely justified," Jim Amormino, a sheriff's department spokesman told ABC NEWS.com. "The deputy had two seconds of contact with the suspect before he started screaming and running into traffic."
"If he hadn't been Tasered, he could easily have been killed by a car. The suspect, the officers, drivers on the road and pedestrians all could have been at risk if the suspect continued into traffic," he said.
Many Taser incidents might well have otherwise required the use of lethal force, and they've thus saved lives, according to Richard Jerome, a lawyer and former Justice Department official who now consults on police accountability.
"Clearly, Tasers are a important tool for law enforcement," Jerome said. "They're used by police departments to lower the incidence of more serious use of force."
In the other incident this week, University of Florida President J. Bernard Machen Tuesday called the Tasering and arrest of student Andrew Meyer "regretful" and launched a university inquiry, calling on the state police to investigate.
Monday officers took down Meyer before a roomful of people after the college senior grabbed a microphone and asked Kerry a series of questions, including whether he'd been a member of Yale's secret society Skull and Bones.
After Meyer was on the ground and surrounded by officers, he is a heard to say, on a widely circulated video of the incident, "Don't Tase me bro!"
In another filmed incident that went viral on the Internet this week, an Ohio woman was Tasered earlier this month multiple times, including while handcuffed and seated in the back of a police cruiser.
Heidi Gill, 38, said she feared for her life when Police Officer Rich Kovach Tasered her over and over again after a bar argument in Warren, Ohio.
"I didn't think I was going to make it out of there. I just wanted this pain to stop. This electrocuting and Tasering. ? I didn't know what Tasering even was," Gill said.
Kovach was placed on paid leave pending an investigation.
Each of these incidents demonstrates what police officers already know: Interactions between the police and suspects can be volatile and require the officer to quickly sum up a situation.
Police departments each develop their own "use of force continuums," a series of escalating steps that officers employ to determine when and how much force should be deployed against a suspect.
"Some departments put Tasers pretty high on their force continuum, some pretty low down at the level of pepper spray," said Mona Cadena, the deputy director of Amnesty International's western region.
"Cops, of course, will come into contact with violent individuals and have to respond, but they should always use the minimum … force for the threat that is posed. The question out there is: Is it appropriate to use a Taser on a student who is just being a nuisance, or on senior citizens or children or pregnant women."
Amnesty International has been tracking Taser use in the United States since 2001 and says it is difficult to know the medical risks involved because little independent research has been done. It is also difficult to know whether Tasers are being misused because there is no national standard for keeping track of their use.
"Cops have to register firearms and record every time they discharge them. That information then goes into a national database, but there is nothing like that for Tasers. We're concerned with use and reporting and a lack of regulation," she said.
Taser International said it has created a weapon that when used properly can safely and effectively subdue suspects. Moreover, every weapon it produces, unlike, say, a billy club, electronically registers the time, date and duration of a shock.
Recent incidents, including the April 2006 death of a 56-year-old, wheelchair-bound Florida woman who was Tasered 10 times and later died, stirred controversy for the company. However, the manufacturer says it is the police who should be taking the heat.
"We don't teach use of force techniques. We train the trainers and give them as much information as possible to use it safely," said Steve Tuttle, spokesman for Taser International. "Every agency is going to use it differently, based on their own use-of-force guidelines. Sometimes it will be used against people passively resisting, other times against more active resistance," he said.
Tuttle said that in some cases multiple shocks are necessary and can be done safely.
"Multiple applications have good outcomes in arresting someone safely. We've shown that multiple applications are not dangerous. We don't limit the number of bullets in a gun," he said.
Tuttle said it was frustrating that every controversial use has reporters focusing on the company instead of the agencies using the weapon. Gun manufacturers are not called to comment every time cops misuse their firearms, he said.
"The media never reports on all the planes that land safely. But thousands of Tasers are used safely every day. Every Taser has a computer chip that records the time, date and length of duration."
No federal agency keeps track of injuries or deaths related to Taser usage. Amnesty International claims that since 2001 it has registered 270 "Taser-related deaths," or incidents in which a Taser was used prior to a suspect's death "but not deemed the primary cause of death by a coroner or medical examiner."
Amnesty International has recorded only seven cases in which a medical professional directly linked a Taser to death.
"In 2004, there were 48 related deaths. In 2005, there were 65 related deaths. That's a 27 percent increase," said Amnesty's Mona Cadena. "More cops using more Tasers equals more deaths. We have to ask ourselves: Is the Taser really nonlethal?"
Taser has its own figures. In the 54 wrongful death cases brought against the company, it has won every single one.
"We're 54 and 0 in wrongful deaths cases. In a courtroom sound bytes don't count. We have time to debunk the junk science and demonstrate the safety of our product," Tuttle said.
In many Taser-related deaths, the victims were using drugs, were overweight and in an already excitable state some doctors call "excited delirium."