The police department in Ferguson, Mo., has finally released the name of the officer who shot and killed unarmed 18-year-old Michael Brown there last Saturday. It is Darren Wilson. The news followed days of protests and violent clashes between police and residents over the shooting. Tensions escalated when police used what many criticized as excessive force: tear gas, smoke bombs and rubber bullets, wielded to disperse crowds of protestors already infuriated by the actions of the police. Even though some protestors were allegedly throwing bottles and Molotov cocktails, “it’s an extreme response,” says Stephen Coleman, senior lecturer on ethics and leadership at the University of New South Wales in Australia, who has worked on educating police officers about nonlethal weapons.
So-called nonlethal weapons such as rubber bullets and tear gas to control crowds have become increasingly common tools among America’s police forces, Coleman says, which is raising concern. The weapons can inflict immense pain and physical injury, and can potentially (though rarely) kill individuals on the receiving end. For example, rubber bullets, made from various materials including rubber and plastic, deliver a hit or punch meant to incapacitate a person. “They deliver varying degrees of impact energy to stop someone from throwing rocks or knocking out windows,” says Major Steve Ijames, a retired officer from the Springfield, Missouri, Police Department. “They’re basically used to get people to leave an area.” Depending on the shot distance and type of bullet, the projectiles cause varying amounts of pain and injury, and can even break bones. If rubber bullets hit someone’s throat or neck, or are fired at close range, they can kill. An estimated 15 people in the U.S. and Canada have died from this weapon since 1971, Ijames says.
Tear gas is also considered a nonlethal weapon. Although most nations (including the U.S.) banned it from warfare in the 1993 Chemical Weapons Convention because of its great potential for escalation to other gases that are very lethal, such as nerve gas, it is a common crowd-dispersal tool for many governments around the world. The gas comes in a variety of forms, including pepper spray. Law enforcement typically uses CS gas, or 2-chlorobenzalmalononitrile, which causes severe pain and irritation of the skin, eyes and respiratory system. Although tear gas rarely kills, it can cause health problems. “A lot of people exposed cannot breathe properly and have anxiety, because you feel like you’re suffocating,” says Sven-Eric Jordt, a professor of anesthesiology at Duke University. Tear gas is especially dangerous for people with preexisting respiratory conditions like asthma or emphysema, he says.
Although tear gas seems to have relatively short-term effects, researchers have yet to study the long-term consequences for human health. “This is a big concern because tear-gas use has increased worldwide,” Jordt says.
Use of nonlethal weapons is especially problematic because they are hard to target at specific individuals who need to be arrested. Obviously, tear gas affects everyone in the vicinity. Officers often bounce rubber-bullet shots off the ground to reduce the force of a hit, which means they cannot aim with this technique. On Wednesday, a local pastor in Ferguson tried to calm raucous protestors and was later shot by police in the abdomen with a rubber bullet, according to the New York Times. “It’s sort of a nontargeted response,” Coleman says. “So even people who are being completely nonviolent are getting attacked.”
Experts also note that combative tactics that rely on nonlethal weapons tend to escalate situations rather than solve anything. “When people are complaining about the excessive use of force by police, it seems crazy that you respond with excessive force,” Coleman says. Nonlethal weapons, he adds, “become a substitute for the sorts of skills police used when they didn’t have access to nonlethal weapons.” This includes nonconfrontational approaches as simple as trying to talk to and negotiate with people in order to de-escalate a situation. Some critics quoted in various media reports have claimed that the tendency to use nonlethal weapons rose in the past several years in part because police departments received federal funding to enable the purchase of anti-terrorism gear after the September 11 attacks. 
Problematic use of nonlethal weapons seems to be a much bigger issue for U.S. law enforcement than it is in other nations such as Australia, the U.K. and Canada, Coleman says. In Australia, for example, most police don’t have access to the nonlethal weapons used by Ferguson officers and only a few are trained to use such weapons. “It seems that policing in the U.S. in particular," he says, "has turned to the use of force as a first, rather than a last resort.”