On "Law & Order: Special Victims Unit," where he has portrayed Det. Odafin "Fin" Tutuola since the start of its second season, actor/rapper Ice-T notes that "they have cops who show up on the set as advisers, but a lot of times they'll ask me the criminal questions. I've been in the system as much as the cops have, so I'm their other authority on stuff.

"But I know from a director's and producer's point of view, you want to get people that have had life experience on that screen because it does bleed through. Somebody who's led a real sheltered life is going to have a hard time being an actor. You have to have gone through something."

And Ice-T, born Tracy Marrow in Newark, has been through some things. An only child whose parents were both dead before he was 12, Marrow headed west to live with an aunt and came of age on the mean boulevards of South Central Los Angeles.

His life on the street was sandwiched around a four-year Army stint.

Later, the emergence of rap offered Ice-T a way up and out. In high school, he'd become enamored of Robert Maupin Beck, a former pimp and prison-fired novelist who, as Iceberg Slim, detailed the harsh criminal underworld--and inspired Marrow's future handle.

After a few singles on independent labels in the early '80s, Ice-T moved to a major label, Sire, and prophetically titled his 1987 debut "Rhyme Pays." A year later, he wrote the theme for "Colors," a shocking film about corrupt police and Los Angeles gangs and by the end of the decade, seeded what came to be known as "gangsta rap," with his "O.G. Original Gangster" album defining that genre alongside N.W.A.'s "Straight Outta Compton."

In 1991, former N.W.A. rapper Ice Cube and Ice-T made a near simultaneous move from the studio to the silver screen, in "Boyz N the Hood" and "New Jack City," respectively.

In the latter, Ice-T went against typecasting and played an undercover narcotics cop, but the following year he became public enemy No. 1 and the target of national protests over "Cop Killer," a controversial trash-metal track by his rock outfit, Body Count.

In it, Ice-T adopted the persona of a fictional character fed up with police brutality and racism and spoke of being " 'bout to dust some cops off." President Bush called Ice-T's work "sick" and 60 members of Congress spoke out against the song. Police groups threatened to pull their investments out of parent company Time Warner. The track was voluntarily pulled from the album, replaced by "Freedom of Speech/Just Watch What You Say."

"I've always spoken honestly about the police," said Ice-T, adding, "I'm still not the greatest fan of the police. They've got good cops and they've got bad cops and I know that even more now from being on 'Law & Order.' The cops that I attacked in my music? Sometimes we deal with those cops on the TV show, so it's all real."

"There's something authentic about Ice: you believe that he's a cop," said Neal Baer, executive producer and head writer for "Law & Order: SVU," which airs on Fridays and this Saturday at 10 p.m. on NBC.

"I love going on location with him because he stirs up such emotions whenever we go out," Baer said. People just connect somehow, and you see it on the street. We'll shoot in Manhattan or the Bronx or Harlem, and wherever we go, word spreads: Ice is shooting!"

Factually, Ice-T's acting career predates "New Jack City." In the mid '80s, he made brief appearances in the lightweight, low-budget hip-hop films "Breakin,' " "Rappin' " and "Breakin' 2: Electric Boogaloo." The Ice-T of that era was neither the confident actor nor the hardcore rap persona he would be by decade's end.

"When I got on 'New Jack City,' I knew I was acting for hip-hop, carrying a lot more than just Ice-T. I knew if I could pull it off, they were going to look into my genre and give a lot of rappers a chance to act. I was very concerned with not being whack; I tried to get it right."

He did, with roles in "Ricochet," "Trespass" (co-starring Ice Cube), "CB4" and "Surviving the Game" before making the crucial connection with "Law & Order" creator and producer Dick Wolf on "New York Undercover," where he played a drug kingpin on three 1995 episodes.

Later, Ice-T went to Wolf with an idea for a show about a canny ex-con paroled to the FBI to lead a team of fellow con-artists in undercover work--sort of "The Dirty Dozen" and "Mod Squad" meets "The A-Team" and "Charlie's Angels."

"Players," with Ice-T as Isaac "Ice" Gregory, premiered in the fall of 1997 and was canceled after one season. "But Dick Wolf said, 'I wish I had a stronger vehicle for you.' "

He did: Ice-T joined the cast of the first "Law & Order" spinoff in its second season. The series focuses on the seamier side of New York crime, particularly the sex-related offenses handled by the show's special victims unit. This year, the themes have expanded to include elder abuse, child smuggling, mercy killing and child pornography on the Internet.

"I was talking to a friend and he said, 'You're on the sickest show on television!' " Ice-T recalled after having finished "Dom-inance," with "a lot of blood and one of the weirdest twists yet. I always look at Neal Baer and say, you are some weird guys. You all talk about Eminem and Ice-T and all? I'd hate to see you guys in the music business! What would you sing about?"

"Unfortunately, these are stories about human beings, things that have really happened," said Baer. "They're really not about looking for depravity, but about trying to understand the human condition."

Baer, who came to "SVU" in the same season as Ice-T, instituted a wardrobe change. "When I came on, Ice wore suits that seemed to just squeeze him. We decided to move him into the forefront of the show and change his look. So out with the suits and in with the leather jacket and turtlenecks. He's hip, so he's got to look hip."

According to Ice-T, the final makeover occurred when Wolf said " 'Ice, just play you as a cop. If you were a cop, how would you see things, what would you do, what would you say?' There's a reason people like me and they don't want to see me far from that. . . ."

Det. Tutuola was partnered up with cynical, acid-tongued, conspiracy theory-consumed Det. John Munch, a character Richard Belzer played for seven years on the late, lamented series, "Homicide: Life on the Street."

It didn't take long for a quirky chemistry to set in, undoubtedly helped by the fact that both Ice-T and Belzer came from character-driven, storytelling art forms built on fast-on-your-feet improvisation and clever wordplay.

"He came from the rap world and I came from the comedy world," Belzer said. "We were both outsiders and we bonded because, even within our respective art forms, we were both considered radical. It's a rarefied atmosphere and at the risking of seeming immodest, how many people can truly be perceived as rebels and then make it in the mainstream? It's not easy but it's certainly fun to keep your aesthetic and be in the mainstream."

Of his on-screen partner, Belzer said, "Ice has a great screen presence and I think he's just refining that and getting better all the time. He was always good and he was always charismatic but after doing the character for a while, he's adding nuance and it's nice to watch that. And he's very funny. Fin is very dry and witty, but off camera, Ice is lot more expressive and dynamic, and you never know what's going to happen between takes."

In a famous 1992 Rolling Stone cover story for which he posed in a blue policeman's uniform--it was the height of the "Cop Killer' controversy--Ice-T was described as an "occasional actor." These days, he might be described as an "occasional musician."

Since "New Jack City," he's appeared in more than 40 films and last year hosted TLC's "Beyond Tough," a series profiling people in dangerous but heroic jobs--including law enforcement. Just as Ice-T's movie career has been put on hiatus because of his continuing role on "Law & Order: SVU," his music career has seemingly been mothballed because of his acting commitments. Having made eight albums between 1987 and 1996, Ice-T has released only one since, though there's another in the can under the name "Sex, Money & Gunz," featuring Smooth Da Hustler and Trigger Tha Gambler, and he's firing up Body Count again.

Ice-T was a pioneer in another field that has now become a billion dollar a year industry: the hip-hop influenced urban apparel market. The past few years have brought a proliferation of urban collections, from FUBU and Karl Kani to rapper-associated ones such as Rocawear (Jay-Z), Sean John (Sean Combs) and Phat Farm (Russell Simmons). Coming in July: IceWear.

Ice-T was a little ahead of the curve with 1992's Original Gangster Gear, but he didn't have sufficient funding and, he admits, "the line was a little too hardcore. I didn't realize how uptight [retail] stores were, and we had jeans called Mack 10 and Tech 9--a little rough.'

No firearm references this time around. He's working with Manhattan-based Americo Group Inc. to produce a collection of baggy jeans, velour jogging suits and oversized hoodies with an East Coast/West Coast unity theme and a prominent logo: an abstract diamond icon, Ice-T's signature and the motto "Respected Since '83"--the year he released his first single.

"First, you got to remember, I didn't think you could live off of rapping," he says. "When I got into rap, there were no rap stars, it was just underground music. Now, if I got treated any better, people would carry me down the street. I got no issues, no problems. If I got any more respect, I don't know what would happen. I'm living the life."