Two police vehicles were damaged while officers attended an incident in North Yorkshire yesterday.
The force is now seeking witnesses who might be able to help officers to establish how the damage was caused.
A spokesman said it happened between 12.20pm and 1.20pm while the police car and van were parked on Topcliffe Road in Thirsk.
Anyone who has information is urged to contact police on 101, selecting option 2, and asking for TC Katie Shaw.
Information can also be provided by emailing Katie.firstname.lastname@example.org or by calling Crimestoppers anonymously on 0800 555 111.
Please quote the North Yorkshire Police reference 12170066631.