On the morning of May 4, Victor Aponte, a well-behaved youth who earned good grades in high school, walked calmly into the police station on East 102nd Street in Harlem and told the desk lieutenant: "I want to report that I killed my mother."

Two nights before, the 16-year-old confessed, his mother had caught him at home smoking "crack," a purified, highly addictive form of cocaine. A fight erupted, and Aponte told police he grabbed a kitchen knife and in a drug-induced frenzy fatally stabbed his mother nine times, leaving the knife in her neck.

Since then, the potent cocaine derivative that New York officials are calling the city's new drug of choice has been linked to at least eight violent crimes. Many law enforcement authorities also blame the drug for at least part of the 8.3 percent increase in felonies in the first four months of this year.

Virtually unheard of nine months ago on the East Coast, crack has swept affluent and poor neighborhoods alike, tempting children as young as 8 years old. First-time users become addicted quickly, experts say, and are prepared to steal, prostitute themselves, even kill for the next hit.

"I've never seen anything like it," said William Hopkins, a 20-year veteran of the city police force and director of the street research unit of the New York State Division of Substance Abuse Services. "Crack is getting out of control very, very fast. We are, without a doubt, in an epidemic situation that's going to get worse before it gets better."

The crack crisis not limited to New York. The National Cocaine Hotline (1-800-COCAINE), based in Summit, N.J., estimates that 1 million Americans in 25 states have tried crack, known as "rock" on the West Coast. Boston, Detroit, Dallas, Los Angeles, Miami, Philadelphia and San Francisco have reported growing crack abuse.

Police say nearly 90 percent of cocaine sold in Detroit is crack; the estimate is 66 percent in Dallas and 30 percent in San Francisco. It is not yet a widespread problem in Washington, said Sgt. Joseph C. Gentile of the District's police force. The problem drug of choice in the nation's capital is PCP, also known as "angel dust."

Crack accounts for as much as half of all federally prosecuted drug cases in the past eight months here, according to U.S. Attorney Rudolph W. Giuliani, and police report that more than half of all cocaine arrests now involve crack. Marijuana arrests, on the other hand, dropped 92 percent in the first four months of this year compared with the same period last year, and heroin arrests fell 88 percent.

Last month, Police Commissioner Benjamin Ward formed a special 101-member squad to combat crack. So far, 135 street dealers have been arrested, according to its leader, Deputy Inspector Martin O'Boyle.

Experts say crack's explosion onto the drug scene here and elsewhere can be traced to its affordability, accessibility and the fact that it is smoked -- an attractive attribute for users leery of hypodermic needles that can spread the deadly acquired immune deficiency syndrome.

Crack is five to 10 times more powerful than snorted cocaine. Sold in small plastic vials containing one or two rocks for $10 to $20, crack can be made by mixing powdered cocaine with baking soda and water over a hot flame. The left-over residue is dried into small, white "rocks" resembling pieces of crumbled soap. The rocks make a crackling sound as they are smoked.

Within 10 seconds, a user experiences a euphoric rush, followed a few minutes later by a sharp letdown. "There is always a hunger for more," said Dr. Arnold M. Washton, an expert on addiction and the national hot line's director of research. He calls crack the "fast food of drugs."

While crack can cause brain seizures, chronic chest congestion and irreversible lung damage, Washton said the real danger is its hold on addicts' personalities. "Their priorities start to shift, and their lives begin to revolve around getting the next hit of crack," Washton said.

A 19-year-old former user from Jamaica, Queens, says he remembers that feeling well. He suffered three seizures before entering a drug rehabilitation program eight months ago. He is a senior now at the Phoenix House annex high school in Yorktown, N.Y., and asked not to be identified by name.

"The high is the ultimate. I fell in love with it," he said. "I could have died, but I didn't learn my lesson. I still wanted to hit the pipe again . . . . I wanted it every day, all day. All I wanted to do was get that high again. I couldn't stop."

Police and drug experts tell chilling tales of crimes committed by addicts, many of whom have no previous police record, to feed the habit or because of the high. A 14-year-old girl reportedly had sex with 20 men on a South Bronx rooftop to get money for crack. A 24-year-old man killed his girlfriend with a nine-inch butcher knife after smoking six pellets of crack.

"It made me do things I never did before," said an 18-year-old junior at the Phoenix school. The young woman, who asked not to be identified, said she began using drugs when she was 13, stealing appliances from her mother, shoplifting dresses and using her brother's gun to rob discotheque patrons to support her $500-a-day habit.

Crack's increasing use among adolescents frightens school officials. On a recent sweep of street dealers, 18 of 44 arrests took place within 1,000 feet of a school.

"Whoever masterminded this whole crack thing probably had a PhD in child psychology," said Levander Lilly, director of drug counseling and prevention programs in the city's schools. "It's much easier to get a child to smoke a pipe than it is to get them to inject heroin into their arms."

Big dealer profits have made the fight against crack more difficult: An ounce of powdered cocaine, bought at $2,000, can generate about $2,000 in profit when turned into 250 vials of crack sold at $15 apiece. And it can be manufactured and sold by almost anyone who can buy cocaine on the street.

"Crack is clearly becoming a national issue," said Robert Stutman, head of the New York field division of the Drug Enforcement Administration. "The reason it is so attractive to New Yorkers will be no different in other communities. If we aren't careful, this will become the drug of choice in the United States, and that will be devastating."