A man has been arrested after he was seen trying to get into parked vehicles at 3am in Kenilworth Drive area of Croxley Green.
Police sent in a helicopter to track down the suspects after reports of suspicious behaviour in a neighbourhood last night.
Hertfordshire Constabulary says the suspect was detained and found to also have a car key on him which matched another vehicle that was reported as stolen from Watford earlier this week. That vehicle has since been recovered.
The 23-year-old man remains in police custody at this time.
Enquiries are ongoing to trace the other suspect that was able to get away overnight.
Anyone with information is asked to visit herts.police.uk/report or call 101 quoting ISR 64 of June 23.
Other car theft news:
Police were alerted to a blue Land Rover Range Rover Sport which was reported stolen from Chestnut Avenue. Officers quickly located and recovered the vehicle in Rickmansworth in the early hours of Sunday morning (20 June).
Now under forensic analysis and an investigation has been launched. Any witnesses or anyone with information is urged to contact the police quoting crime reference 41/46129/21.
And, Two Range Rovers stolen on Monday night in Harpenden were recovered and three men have been arrested on suspicion of theft of motor vehicles.
One was stolen at 1.55am from Oak Way and a second at 2.05am from Dellcroft Way.
The men arrested are a 20-year-old from Ilford, a 36-year-old from London and a 39-year-old from St Albans.
The vehicle stolen from Dellcroft Way was spotted by officers in London Road, St Albans. The driver failed to stop but the occupant decamped and was arrested. The Oak Way Range Rover was found parked and unattended near London Road.
The thefts are being linked.