TRENTON Steven Comeau knows the turmoil that can be created when someone has enough data to impersonate you. In November 2001, the South Brunswick man was surprised to learn that he was considered the owner of a small apartment house in Brooklyn, N.Y., and was behind on his mortgage payments. Comeau also had a $500 balance on a new credit card he never asked for and owed $8,000 on three cell phones he didn’t have. Like millions of other Americans, Comeau was a victim of identity theft. A new state law that takes effect Sunday aims to crack down on such crimes by allowing residents to freeze access to personal credit reports. Under the new law, New Jersey residents can control access to their own credit reports. Without access to ``frozen’’ reports, an identity thief cannot obtain a mortgage or a credit card using someone else’s name, even with the victim’s Social Security number. Consumers wishing to freeze access to their reports are required to inform the credit reporting agencies by overnight or certified mail since the letter includes their Social Security number. Each agency, Experian, Equifax and TransUnion, requires different information in addition to the Social Security number, so consumers should contact them before writing. The new law also requires businesses of all sizes to destroy unneeded consumer records and report security breaches to customers. And Social Security numbers can no longer be used on identity badges, membership cards or used to allow the holder to gain access to products or services. Consumer advocates say New Jersey’s law is among the best in the nation, where some believe up to 10 million people a year are victimized by identity theft. Although it costs nothing to freeze a credit report the new law lets consumers be charged $5 to ``thaw’’ the report. Since there are three major credit rating companies, it could cost consumers $15 when they apply for a loan or get a new credit card. The law also requires that a resident’s local police department take a reports on identity theft. Although South Brunswick police took Comeau’s report, some departments refuse, claiming that the crime did not take place within their jurisdiction.