It may seem like a no-brainer, but according to the Suffolk County Police Department many North Shore residents are forgetting to lock their cars.

The department recently launched a new “Lock It or Lose It!” campaign aimed at encouraging residents to lock their parked vehicles.

Police Commissioner Tim Sini said the department is looking for the public’s help to bring down this type of petit crime.

“Every day, the hard-working men and women of the Suffolk County Police Department are out there in force doing their best to keep crime down,” he said in a statement. “Oftentimes, though, it is the partnership with the public that helps get us the results. The first line of defense is [to] lock your doors. Also, make sure if there are valuables in your car, they are not in plain view.”

Although it may seem simple, many Long Islanders are leaving their cars unlocked.

A periodic check of Suffolk County police reports will turn up dozens of incidents of items stolen out of unlocked cars parked in driveways, parking lots or other locations.

The department has partnered with Suffolk County Crime Stoppers and multiple television and radio stations to routinely broadcast a 30-second public service announcement during the next month to remind residents to lock their vehicles.

“Unlocked vehicles give criminals an additional bonus of stealing sensitive personal documents resulting in identity theft without a victim realizing the fact until it’s too late,” Crime Stoppers President Nick Amarr said in a statement. “The Lock it or Lose It campaign is a way to remind residents how they can help prevent becoming the victim of a crime.”

According to the department, most vehicle break-ins are crimes of opportunity, and if a vehicle is locked, a criminal will usually move on. Locking car doors should substantially decrease the likelihood of being victimized. Approximately 312 cars are targeted every month in Suffolk County, according to a statement from the police.

On the North Shore, cell phones, wallets, credit cards, cash, GPS, cell phone chargers, laptops and tablets are among the most common items taken when someone breaks into a car.

Campaigns just like Suffolk County’s are becoming the norm throughout the country, as police departments in many states try to remind residents they can help reduce crime in their neighborhoods.