FROM the way police entered the house—helmeted and masked, guns drawn and shields in front, knocking down the door with a battering ram and rushing inside—you might think they were raiding a den of armed criminals. In fact they were looking for $1,000-worth of clothes and electronics allegedly bought with a stolen credit card. They found none of these things, but arrested two people in the house on unrelated charges.

They narrowly avoided tragedy. On hearing intruders break in, the homeowner’s son, a disabled ex-serviceman, reached for his (legal) gun. Luckily, he heard the police announce themselves and holstered it; otherwise, “they probably would have shot me,” he says. His mother, Sally Prince, says she is now traumatised.

Gary Mikulec, chief of the Ankeny, Iowa police force, which raided Ms Prince’s home in January, said that the suspects arrested “were not very good people”. One had a criminal history that included three assault charges, albeit more than a decade old, and on his arrest was found to have a knife and a meth pipe.

It is easy to see why the police like to be better armed than the people they have to arrest. They risk their lives every day, and are understandably keen to get home in one piece. A big display of force can make a suspect think twice about pulling a gun. “An awful lot of SWAT tactics are focused on forcing the suspect to surrender,” says Bill Bratton, New York’s police chief.

But civil libertarians such as Radley Balko, the author of “Rise of the Warrior Cop”, fret that the American police are becoming too much like soldiers. Special Weapons and Tactics (SWAT) teams (ie, paramilitary police units) were first formed to deal with violent civil unrest and life-threatening situations: shoot-outs, rescuing hostages, serving high-risk warrants and entering barricaded buildings, for instance. Their mission has crept.

Boozers, barbers and cockfighters

Peter Kraska, a professor at Eastern Kentucky University’s School of Justice Studies, estimates that SWAT teams were deployed about 3,000 times in 1980 but are now used around 50,000 times a year. Some cities use them for routine patrols in high-crime areas. Baltimore and Dallas have used them to break up poker games. In 2010 New Haven, Connecticut sent a SWAT team to a bar suspected of serving under-age drinkers. That same year heavily-armed police raided barber shops around Orlando, Florida; they said they were hunting for guns and drugs but ended up arresting 34 people for “barbering without a licence”. Maricopa County, Arizona sent a SWAT team into the living room of Jesus Llovera, who was suspected of organising cockfights. Police rolled a tank into Mr Llovera’s yard and killed more than 100 of his birds, as well as his dog. According to Mr Kraska, most SWAT deployments are not in response to violent, life-threatening crimes, but to serve drug-related warrants in private homes.

He estimates that 89% of police departments serving American cities with more than 50,000 people had SWAT teams in the late 1990s—almost double the level in the mid-1980s. By 2007 more than 80% of police departments in cities with between 25,000 and 50,000 people had them, up from 20% in the mid-1980s (there are around 18,000 state and local police agencies in America, compared with fewer than 100 in Britain).

The number of SWAT deployments soared even as violent crime fell. And although in recent years crime rates have risen in smaller American cities, Mr Kraska writes that the rise in small-town SWAT teams was driven not by need, but by fear of being left behind. Fred Leland, a police lieutenant in the small town of Walpole, Massachusetts, says that police departments in towns like his often invest in military-style kit because they “want to keep up” with larger forces.

The courts have smiled on SWAT raids. They often rely on “no-knock” warrants, which authorise police to force their way into a home without announcing themselves. This was once considered constitutionally dubious. But the Supreme Court has ruled that police may enter a house without knocking if they have “a reasonable suspicion” that announcing their presence would be dangerous or allow the suspect to destroy evidence (for example, by flushing drugs down the toilet).

Often these no-knock raids take place at night, accompanied by “flash-bang” grenades designed temporarily to blind, deafen and confuse their targets. They can go horribly wrong: Mr Balko has found more than 50 examples of innocent people who have died as a result of botched SWAT raids. Officers can get jumpy and shoot unnecessarily, or accidentally. In 2011 Eurie Stamps, the stepfather of a suspected drug-dealer but himself suspected of no crimes, was killed while lying face-down on the floor when a SWAT-team officer reportedly tripped, causing his gun to discharge.

Householders, on hearing the door being smashed down, sometimes reach for their own guns. In 2006 Kathryn Johnston, a 92-year-old woman in Atlanta, mistook the police for robbers and fired a shot from an old pistol. Police shot her five times, killing her. After the shooting they planted marijuana in her home. It later emerged that they had falsified the information used to obtain their no-knock warrant.

Big grants for big guns

Federal cash—first to wage war on drugs, then on terror—has paid for much of the heavy weaponry used by SWAT teams. Between 2002 and 2011 the Department of Homeland Security disbursed $35 billion in grants to state and local police. Also, the Pentagon offers surplus military kit to police departments. According to Mr Balko, by 2005 it had provided such gear to more than 17,000 law-enforcement agencies.

These programmes provide useful defensive equipment, such as body armour and helmets. But it is hard to see why Fargo, North Dakota—a city that averages fewer than two murders a year—needs an armoured personnel-carrier with a rotating turret. Keene, a small town in New Hampshire which had three homicides between 1999 and 2012, spent nearly $286,000 on an armoured personnel-carrier known as a BearCat. The local police chief said it would be used to patrol Keene’s “Pumpkin Festival and other dangerous situations”. A Reason-Rupe poll found that 58% of Americans think the use of drones, military weapons and armoured vehicles by the police has gone “too far”.

Because of a legal quirk, SWAT raids can be profitable. Rules on civil asset-forfeiture allow the police to seize anything which they can plausibly claim was the proceeds of a crime. Crucially, the property-owner need not be convicted of that crime. If the police find drugs in his house, they can take his cash and possibly the house, too. He must sue to get them back.

Many police departments now depend on forfeiture for a fat chunk of their budgets. In 1986, its first year of operation, the federal Asset Forfeiture Fund held $93.7m. By 2012, that and the related Seized Asset Deposit Fund held nearly $6 billion.

Mr Balko contends that these forfeiture laws are “unfair on a very basic level”. They “disproportionately affect low-income people” and provide a perverse incentive for police to focus on drug-related crimes, which “come with a potential kickback to the police department”, rather than rape and murder investigations, which do not. They also provide an incentive to arrest suspected drug-dealers inside their houses, which can be seized, and to bust stash houses after most of their drugs have been sold, when police can seize the cash.

Kara Dansky of the American Civil Liberties Union, who is overseeing a study into police militarisation, notices a more martial tone in recent years in the materials used to recruit and train new police officers. A recruiting video in Newport Beach, California, for instance, shows officers loading assault rifles, firing weapons, chasing suspects, putting people in headlocks and releasing snarling dogs.

This is no doubt sexier than showing them poring over paperwork or attending a neighbourhood-watch meeting. But does it attract the right sort of recruit, or foster the right attitude among serving officers? Mr Balko cites the T-shirts that some off-duty cops wear as evidence of a culture that celebrates violence (“We get up early to beat the crowds”; “You huff and you puff and we’ll blow your door down”).

Others retort that Mr Balko and his allies rely too much on cherry-picked examples of raids gone wrong. Tragic accidents happen and some police departments use their SWAT teams badly, but most use them well, says Lance Eldridge, a former army officer and ex-sheriff’s deputy in Colorado.

It would be easier to determine who is right if police departments released more information about how and how often they deploy SWAT teams. But most are extremely cagey. In 2009 Maryland’s governor, Martin O’Malley, signed a law requiring the police in his state to report such information every six months. Three published reports showed that SWAT teams were most often deployed to serve search warrants on people suspected of crimes involving drugs and other contraband, but the law is set to expire this year. Utah’s legislature has passed a similar measure; it awaits the governor’s signature.

No one wants to eliminate SWAT teams. Imminent threats to human life require a swift, forceful response. That, say critics, is what SWAT teams should be used for: not for serving warrants on people suspected of nonviolent crimes, breaking up poker games or seeing that the Pumpkin Festival doesn’t get out of hand.