If there are any injuries, it's always a good idea to call the police to ensure everyone involved receives proper medical attention and to have an official record of the incident. If the damages to the vehicles involved are significant, it may also be beneficial to file a police report to help your insurance company process any claims related to the accident.
When in doubt, it's best to contact your local police station or the non-emergency line to inquire about the requirements for reporting accidents in private parking lots in your area.
