The threat of imprisonment rarely deters armed robbers because most believe the chances of getting caught are very low, researchers have discovered.
Picking easy targets is a priority, and many robbers say they are prepared to shoot their way out if necessary. However, only about half carry a gun capable of delivering a lethal shot.
Interviews with hundreds of convicted armed robbers by researchers at Leicester University's Scarman Centre, which hosted an international crime conference this week, revealed that, contrary to popular belief, most robberies do not involve a lot of planning.
This is because many of the criminals involved think that, in the words of one robber, "all you have to do is walk up to a counter and ask for money from those who have been told to give it to you".
Martin Gill, director of the Scarman Centre and author of a book on the findings, Commercial Robbery, said some robbers are lulled into a false sense of security by deducing from television programmes such as the BBC's Crimewatch that robbery is easy and low risk.
"They can see how poor many of the security camera shots are, and it is clear to them that the police haven't a clue who has committed the crime," Dr Gill said.
This false impression sometimes leads robbers to be so careless as to give themselves away. In one case, a man robbed a bank so quickly that his getaway driver had no time to fit false number plates. The robber also left behind a note demanding money that had his address on it.
Few robbers are troubled by the effect their actions might have on their victims. Some believe they are actually doing their victims a favour by giving them something to talk about in their otherwise dull lives.