Is there a genre more exhausted, or tougher to kill, than the action comedy? Since 1982's 48 Hrs., at least, countless actors have staggered through a formula that rarely works, awkwardly mixing wisecracks and gunplay until they settle in for an inevitable chase scene and a high-five-filled epilogue. Occasionally, a decent film slips through, but for every one that aspires to be Beverly Hills Cop, most end up like Beverly Hills Cop II or, worse, Showtime. Proving that even an overqualified cast and crew can only squeeze so many thrills and giggles out of wrong-way car chases and mismatched partners, Hollywood Homicide pairs gruff veteran Harrison Ford with eccentric greenhorn Josh Hartnett in a film directed and co-written (with Robert Souza) by Bull Durham's Ron Shelton. Inspired by funny stories gathered while researching Dark Blue, his flawed but worthwhile Rodney King-era drama, Shelton's latest at least has the right idea: It lets the plot take a back seat to the colorful characters who inhabit an LAPD force continually distracted by the city it protects and serves. With too much downtime and not enough money to make ends meet, Ford has cultivated a real-estate sideline that is, in its own way, just as hazardous as the flying bullets of his day job. Meanwhile, Hartnett moonlights as a yoga instructor to meet women, but harbors movie-star aspirations. As he prepares for an acting showcase and Ford struggles to unload a property in the gaudily neo-classical neighborhood of Mt. Olympus, the two get called in to solve the nightclub murder of a rap group (none-too-convincingly named "H2O Klick"). Hollywood Homicide boasts the sprightliest Ford performance in years, the first suggestion that Hartnett may have a knack for deadpan comedy, and a pleasingly eccentric cast: It's unlikely that a movie will ever again feature Master P sharing scenes with Martin Landau (playing a Robert Evans-like producer). Shelton makes the most of such only-in-L.A. moments, and similarly makes the most of L.A., exploring neighborhoods rarely used in even the most over-filmed city in the world. But though Hollywood Homicide is never less than competent, the moments don't add up in the end, and by the time Ford mounts a child's bicycle in the never-ending chase finale, genre conventions have pretty well bulldozed the personality that separates Hollywood Homicide from, say, Bad Company. Which raises another question: Why send Shelton, Ford, and Hartnett (not to mention Lena Olin and Lolita Davidovich) to do a job that a C.S.I. vet, Jim Belushi, and a lesser Wayans brother could have handled just as well?