Using a SWAT raid to arrest a subject in cases where the police also want to seize evidence isn't at all uncommon in the US these days. The ostensible idea is that speed and ferocity is needed to capture evidence before criminals can destroy it. In practice I think the situation is more that police departments feel they need need SWAT teams because of terrorism, etc. But once they have them they start looking for chances to use them so the members don't get bored. The police in the US are required to knock on the door and announce themselves before conducting a raid which would interfere with the police starting the suspects and getting them before they could, say, flush their drugs down the toilet. Thankfully for the police there's no requirement for how loudly they have to knock, so I don't think I've ever heard of a case where the suspect or neighbors heard them do this. There are some states where over half of police searches are done by tactical squads bursting in behind a battering ram.
As you mention this is quite common in the U.S. These "high-risk" warrant teams are used all the time for serving narcotics warrants on non-violent offenders. They also commonly get the wrong address or the wrong suspect with tragic results. Take a peek at the map of botched paramilitary raids for a sobering look at what happens when the police screw up: http://www.cato.org/raidmap
