New Jersey's heroin was found to be the purest in the nation for the second straight year, a dubious distinction that has sparked concern in the medical and law enforcement communities. Federal Drug Enforcement Agency tests of heroin samples obtained from New Jersey streets showed 71.4 percent purity in 2002, nearly twice the national average. In the 2003 report, due out soon, New Jersey again will hold the top spot, DEA spokesman Rusty Payne told The Star-Ledger of Newark. "You can't buy any better heroin in the world than you can buy in New Jersey," said special agent Michael Pasterchick.