Four people have been arrested in connection with a string of 40 thefts from vehicles since June 1 in Bethesda neighborhoods south of River Road between Goldsboro Road and Little Falls Parkway.

As they announced the arrests, police also urged residents to stop making themselves easy marks by leaving valuables in their cars and, as in two car thefts that are part of the recent crime spree, to stop leaving keys in cars.

Two 17-year-old male juveniles from Silver Spring were arrested Thursday at about 2:30 a.m. along with Kiele Martin, 19, of Hyattsville, and Tiara Groom, 20, of Bladensburg, Montgomery County Police said. Each was charged with possession of burglar’s tools with the intent to break and enter a motor vehicle.

Police said they had “no evidence to suggest that force was used to enter any car,” in the run of thefts that involved 45 vehicles.

“I need everyone to step up to the plate,” and follow crime prevention rules, Captain David Falcinelli wrote in an open letter Thursday to residents of the Bethesda district he commands. Falcinelli likened the neighborhoods’ allure for thieves to the appeal of a favorite restaurant that draws return visits because it offers what visitors are looking for. Thieves “like how easy it is to get into vehicles and the ready availability of items to steal,” Falcinelli wrote.

Falcinelli thanked residents who were vigilant but wrote “I implore you to talk to your neighbors to make sure everyone is doing the same.”

His tips: remove valuables or hide them from plain sight in cars; lock doors to cars, garages, homes, windows and don’t leave car keys in a car.