THE NUMBER OF CAR THEFTS HAS INCREASED CONSIDERABLY IN THE NETHERLANDS. TO STUDY THIS GROWING PROBLEM POLICE REPORTS OF A SELECTED SAMPLE OF 23 MUNICIPALITIES FOR THE YEARS 1970-74 WERE EXAMINED, AND INTERVIEWS WERE CONDUCTED WITH 12 VICTIMS WHOSE CARS HAD BEEN STOLEN AND 37 CAR THIEVES AND JOY RIDERS. THE FOLLOWING ASPECTS INCREASED THE CHANCES OF CARS BEING STOLEN: (1) BRAND AND TYPE OF CAR, (2) QUALITY OF THE CAR, (3) METHOD OF LOCKING THE CAR, (4) EASE OF OPENING AND STARTING THE CAR, AND (5) THE OPPORTUNITIES CREATED BY OWNERS WHO NEGLECT TO LOCK THEIR CARS OR CLOSE THE WINDOWS. MOST CARS WERE STOLEN OVER THE WEEKEND, IN THE EVENING OR AT NIGHT WHEN IT WAS DARK. IF THE CAR WAS LOCKED, THIEVES USED SUCH DEVICES AS SCREWDRIVERS AND WIRES TO OPEN THE CAR. LITTLE TROUBLE WAS ENCOUNTERED IN STARTING THE CARS; THE TECHNIQUE WAS USUALLY LEARNED FROM A FRIEND OR THROUGH PRACTICE. MOST CARS WERE FOUND BACK IN THE VICINITY FROM WHICH THEY HAD BEEN STOLEN WITHIN 2 WEEKS. MANY OFFENDERS COMMITTED THEIR CRIME IN A DISORGANIZED AND IMPULSIVE FASHION, OFTEN AFTER AN EVENING OUT AND THE USE OF ALCOHOL. THE OPPORTUNITY TO COMMIT A CAR THEFT SHOULD BE LIMITED AS MUCH AS POSSIBLE. THIS COULD BE ACHIEVED BY IMPOSING A FINE ON CAR OWNERS WHO LEAVE THEIR CARS UNLOCKED AND BY PROTECTING CARS WITH EXTRA LOCKS ON STEERING MECHANISMS OR GEAR-BOXES. BETTER INFORMATION TO THE PUBLIC ABOUT THE OCCURRENCE AND NATURE OF THIS CRIME COULD HAVE A POSITIVE EFFECT AS WELL. --IN DUTCH. (WVK)