Police are searching for a teenage boy who escaped from police custody on Bank Holiday Monday.
Michael Casey, 17, from Waveney, Hemel Hempstead, was arrested the previous day on suspicion of theft of a motor vehicle and driving while qualified following an incident in Belswains Lane, Hemel at around 4.50pm.
He was taken to Hatfield Police Station for questioning and escaped custody at around 2.30pm on Monday.
Searches are being carried out to trace him with the assistance of dog units and the helicopter, and anyone who sees him or who knows of his whereabouts is asked not to approach him but to contact police immediately. It may be he has found access to a vehicle.
When he was last seen he was wearing a grey tracksuit and bright yellow sock. He was not wearing shoes.
The circumstances around how he managed to escape are currently being investigated.
Anyone with any information should contact Herts Police on 101.