With “Showtime,” director Tom Dey proves that his first foray – the lively “Shanghai Noon” – was no fluke. In fact, if he’s not careful, Dey may be confused as Hollywood’s new “buddy cop” director in certain circles, which would be an insult if he didn’t comprehend the formula so well.

This time around, mismatched cops Trey Sellars (Eddie Murphy) and Mitch Preston (Robert De Niro) are recruited for the latest reality-based TV show, a “Cops” clone fashioned by an optimistic producer (Rene Russo) for an out-of-touch network. An actor by day, Sellars appears to have studied the “Police Academy” movies instead of his training manual. He sees the program – dubbed “Showtime” – as his ticket to stardom. Straight-laced Mitch, however, merely seeks to solve his current case, a thin set-up involving a generic Eastern European thug who’s manufacturing hand cannons for drug dealers.Despite the intended dynamic duo motif, “Showtime” is Murphy’s vehicle from the get-go. Sly, sharp and frequently funny, Murphy displays a rare return to “48 Hours” form, channeling the cocksure attitude of Reggie Hammond, or the playful confidence of Axel Foley. Meanwhile, the film’s screenplay (credited to three writers) allows De Niro to linger behind and voice the sentiments we’ve always thought during these formulaic buddy cop dramas. By feigning interest, he draws us in. He’s the perfect foil to Murphy’s raw enthusiasm.When “Showtime” attempts to actually further its story – as opposed to pointing a camera at an improvising Murphy – it relies on many of the clich