Not a bad idea, making a ghetto gangland rehash of "Donnie Brasco," that surprisingly powerful Johnny Depp-Al Pacino picture from 1997 about an FBI man deep undercover in the mob.

A story about a cop losing himself in the ambitious, low-level mafioso character he creates as his cover, that flick followed its hero's discovery of the gray areas between right and wrong, and watched his loyalty split between duty and friendship as he immersed himself in mob life.

"In Too Deep" is a strikingly similar yarn, set within a powerful Cincinnati street gang run by a bad-ass cocaine kingpin who calls himself God (LL Cool J). The cop, played here by Omar Epps ("The Mod Squad"), is plucked straight out of the academy for this infiltration assignment, based on his background as a street tough and the fact that he's new to Cinci, so there's no one to blow his cover.

He rises rapidly through God's organization, before long becoming his right hand man (where are all this guy's lieutenants?), all the while making weekly reports to his police captain (Stanley Tucci).

But while Epps is a talented actor and has a valuable and innate ability to put across hardness and concern in a single facial expression, his inner turmoil never comes across as clearly as it should. The conflict -- which is ostensibly the crux of the story -- is taken for granted. It never feels like he really is "In Too Deep."

Several of the story elements feel forced, too -- like a throw-away romantic subplot that develops when the captain pulls Epps out for some forced R and R. He meets a pretty artist (Nia Long, "Soul Food") at a community college where he's taking photography classes, but we hardly see her again, except as a reminder of how far he's stepped outside his real life in infiltrating God's ranks.

Even so, director Michael Rymer ("Angel Baby") does weave an effective tapestry of three-dimensional characters (LL gives a surprisingly layered and almost sympathetic performance as the drug lord) and very strong imagery. He employs over-exposed urban and Caribbean colors that give the film a grainy, light-and-dark contrast and he subtly manipulates the audience with images that shake Epps into remembering who he really is.

In one scene, Rymer cuts to a child on a Big Wheel in the middle of a violent confrontation. In another God introduces Epps to a beautiful girl who we see again later, dazed and emaciated after she's become one of his addicts. Epps also has a moving monologue about memorizing the names of all the kids killed in his neighborhood growing up.

But to maintain his hero status, Epps is never shown doing the kinds of things heÕd have to do earning his stripes with the gang. His advancement through the ranks and his kinship with God come too quickly and easily to be entirely believable. It is presumed the audience will recognize the plot and just follow along as the movie skips the kind of scenes that might have better established the danger and adversity of being that far undercover.

Green-lighting this passing-grade variation on a theme was a shrewd move for Dimension Films, Miramax's genre division. It has a proven storyline, a good cast and an urban target audience that probably won't be making comparisons to the deeper and more genuine "Donnie Brasco." But for those who have seen both, "In Too Deep" just can't measure up.