Car theft increased 4 percent annually between 1967 and 1978, while the recovery rate declined from 90 percent to 60 percent and the arrest rate from 28 percent to 15 percent in the same period. Most cases producing arrests involve juveniles, who form a declining fraction of auto thieves. More stolen cars are being systematically renumbered, refitted, and resold by stolen car rings. In chops shop, popular, late model cars are cannibalized and the replacement parts sold. Both vehicle identification number conversions and chop shops are organized and run by professional criminals, with organized crime involvement in chop shops increasing. In addition, insurance companies estimate that 25 percent of all reported thefts are fraudulent. Auto fraud schemes include permissive thefts, thefts which never occur, registration of wrecks which are subsequently reported stolen, and multiple claims for a car insured with two or more companies. Investigating auto theft is given low priority in most police departments. However, the 1979 Motor Vehicle Theft Prevention Act, still in committee, may help reduce auto thefts by providing that vehicle identification numbers be stamped on every major vehicle component, not just on the engine and transmission. In addition, individual States and police departments have initiated their own auto theft reduction programs, including special police training, sting operations, and incentives to police officers recovering vehicles or making arrests. The Worcester Police Department's (Massachusetts) information and use of a plain clothes auto theft squad has reduced that city's thefts by 64 percent.