Police are investigating two attempted arson offences on the same night in Hemel Hempstead.
And the force has now released an image of a man they would like to speak to as part of their enquiries.
The incidents happened on Tannsfield Drive just after 8.40pm on Monday April 16.
An offender first approached a Skoda Octavia, which was parked on the driveway of a property, and poured petrol on the bonnet.
They then walked up to a second car, a silver BMW, which was parked on an adjacent driveway, and did the same before making off in the direction of Ellingham Road.
If you can identify the person pictured, or have any further information that could assist the investigation, please call 101, and quote crime reference number D1/18/3174.
Alternatively, you can contact the independent Crimestoppers anonymously on 0800 555 111 or online at www.crimestoppers-uk.org.