Why is the Avalon Police Department chalking tires of cars parke

Avalon - Why is the Avalon Police Department chalking tires of cars parked on Dune Drive when the majority of parking spots are empty? There were only a handful of spots occupied this weekend, June 3-4 during the day and it seems ridiculous to see an Avalon police officer recording the license plates and times of each vehicle parked and marking the tires with chalk.