Images of five people have been released by police as they investigate a series of thefts from shops.
There has been a 67 per cent increase in shoplifting in the St Albans area compared to this time last year.
And police wish to speak to a number of people who may know something about particular incidents.
Detective Inspector Pete Frost said: “Many people think shoplifting is a victimless crime, but theft costs us all with increased shop prices.
“Many shops now have CCTV. If we are unable to identify people we would like to speak to in connection with offences from the CCTV, we will put the images on Facewatch ID, which is an app anyone can download.”
He added: “I would like to ask members of the public to report anyone they see shoplifting to a member of staff in the shop – there’s no need to confront them.
“And secondly, I’d like to ask the public to download the Facewatch app and see if they recognise anyone.
“If you do, it’s a simple process to offer up a name and/or address. I’d also be interested to hear from anyone who can let us know who is selling stolen property.”
Since April 1, 2016, there have been 368 shopliftings in St Albans, Harpenden and London Colney – an increase of 148 from last year.
You can see Facewatch ID at www.facewatch.co.uk/cms/police and you can download the app on an Android or iPhone.