Officers have released CCTV images of two men they would like to identify after tools were stolen from a van in Tring.
The incident took place on Wingrave Road between 7pm on Friday, December 13 and 7am on Saturday, December 14.
Police would like to speak with the men in the images as they were in the area at the time and could provide vital information towards the investigation.
Anyone who recognises these people is asked to report information online at herts.police.uk/report, speak to an operator in the Force Communications Room via online web chat at herts.police.uk/contact or call the non-emergency number 101, quoting reference 41/112170/19.
Alternatively, you can stay anonymous by contacting the independent charity Crimestoppers on 0800 555 111 or via their untraceable online form at www.crimestoppers-uk.org.
A police spokesman said: "You can tell us what matters most to you about policing, crime or anti-social behaviour in Hertfordshire using echo. Go to bit.ly/herts-echo and have your say."