By Jim Reed
Newsbeat technology reporter
The scanners use the same technology as mobile phones
Police officers have told Newsbeat that new high-tech fingerprint scanners will cut red tape and reduce the number of people taken into custody.
Under new plans, all police forces in the UK could be using the scanners for on-the-spot identity checks from 2010.
The device, about the size of a Blackberry mobile phone, compares the right and left index finger against the records of 7.5m people with a criminal record.
Similar technology is already in use in American cities like Los Angeles and has been on trial with 20 police forces in the UK for more than a year.
But privacy campaigners and civil rights groups fear the devices might be used to "pick on" members of the public.
Phil Booth from the anti-ID card group NO2ID said: "This implies a completely new power for police to fingerprint you in the street, using an iffy technology.
"If refusing to co-operate can get you arrested, then you would have not just fingerprints but DNA on a criminal database for the rest of your life."
In the field
An updated version of the device will now be rolled out to all UK police forces from 2010 under a scheme managed by the National Policing Improvement Agency.
The devices could have facial recognition capabilities in time for the 2012 London Olympics.
As things stand, police officers must arrest a suspect and take them to a police station to check their fingerprints.
The new system scans the prints remotely and transfers an image to the police national computer using the same picture technology as mobile phones.
The process, which takes around five minutes, tells an officer if a suspect has been arrested in the past.
Bedfordshire police have been trialling a number of units in traffic cars and shopping centres.
Officers have used the scanners alongside automatic number plate recognition systems to check the identities of drivers in cars flagged up as stolen, uninsured or with no MoTs.
Acting Sergeant Chris Leah said: "Every time we use this machine we are saving about two hours of police time at the station.
"Any law abiding member of the public out there should not fear this machine. It's purely aimed at identifying people that for whatever reason do not want to give their true details to us."
But fingerprinting suspects in the street before arrest is still likely to prove controversial.
Some civil liberty groups have reservations about the scanner
Police say laws are in place to prevent any images being stored on a database but civil liberty groups want guarantees the system will delete scans immediately.
Gareth Crossman from Liberty said: "One of the questions it raises is whether it could be linked with the ID card and the database behind the ID card program."
Newsbeat listener Zara from London said: "People might think they are being stereotyped because they are young and vulnerable.
"It's just like a routine check and that makes people abusive unless it's done the right way."
Others are more supportive. Dan, from Croydon, said: "With all the crime going around now, this makes it a quicker and easier way to find out who you are and where you are from.
"If you've got nothing to hide then there's no problem whatsoever."