Washington ? Violent and property crimes dipped in 2002 to their lowest levels since records started being compiled 30 years ago, and have dropped more than 50 percent in the last decade, the Justice Department reported Sunday.

The annual survey by the Bureau of Justice Statistics identified about 23 million crime victims last year, down slightly from the year before and far below the 44 million recorded when studies began in 1973.

The rate of violent crimes — rapes, robberies and assaults — was about 23 victims for every 1,000 U.S. residents 12 or older last year. That compares with 25 victims per 1,000 in 2001 and 50 in 1993.

For property crimes such as burglary and car theft, the rate was 159 crimes per 1,000 last year, down from 167 the previous year and 319 in 1993.

The study examined property and violent crimes except murder, which is measured separately by the FBI. Preliminary FBI statistics for 2002 released in June — based on reports from police across the country — reported a 0.8 percentage point rise in the murder rate compared with 2001.

The Justice Department survey, however, found continuing decreases in every major property and violent crime, crossing all household income, racial and ethnic lines. Crime is down in cities, suburbs and rural areas.

Experts say a number of factors have driven the crime rate down, including a more mature, less violent illegal drug trade, a drop in gang membership and even improved home locks and alarms that deter would-be burglars.

The continuing drop in crime surprises some.

“Everyone thought the numbers would bottom out and then go back up, but it hasn’t happened,” said James Lynch, law professor at the American University Center for Justice, Law and Society.