In less than ten years of making movies, writer/director David Ayer has done a bang-up job of staking out his thematic territory – if you’re looking for a gritty, hard-edged crime drama set on the mean streets of L.A., he’s your man.

Though the South Central, Los Angeles-raised Ayer got his first scripting credits on a WWII action pic (2000’s decent U-571) and an entertainingly cheeseball blockbuster (the original Fast and the Furious), he really came into his own with 2001’s Training Day, a tough-minded inversion of the usual buddy-cop flick clichés about a morally corrupt LAPD detective (Denzel Washington) and his hapless new partner (Ethan Hawke). Bolstered by Washington’s fearsome, Oscar-winning performance, that film (directed by Antoine Fuqua) set down the template for much of Ayer’s most recent work, and he’s been successfully riffing on the same subject matter ever since. This week, he steps behind the camera to direct Street Kings – another L.A.-set cop thriller, this one made from a screenplay co-written by James “L.A. Confidential” Ellroy. Keanu Reeves heads up the cast as a vice detective searching for his partner’s killers and uncovering some dirty business within his own department; Forest Whitaker, Hugh Laurie, and rappers Common and The Game co-star.

Street Kings is Ayer’s second directorial outing, and his first time working with a script that isn’t his own – but if his 2006 debut, Harsh Times, is any indication, he’s as dangerous in the director’s chair as he is with a MacBook.

Harsh Times, which Ayer actually wrote prior to Training Day, is a violent slice-of- life revolving around ex-Army Ranger Jim Davis (Christian Bale), who’s returned to his home turf of L.A. looking for a job in law enforcement. Though he shares his name with the decidedly unthreatening creator of Garfield, however, this Jim is no pussycat – in fact, he’s a total hard case, mentally unstable from his wartime experiences and prone to violent outbursts and criminal behavior. Hooking back up with his slightly more straight-laced buddy Mike (Freddy Rodriguez), Jim ends up blowing his LAPD interview and eventually resorts to petty crime in the old neighborhood; Mike’s career-minded girlfriend Sylvia (Eva Longoria), meanwhile, is immediately suspicious of Jim, and afraid of the influence he has over her already jobless and aimless (but decent) boyfriend. Violently set off by his rejection from the police department, Jim turns increasingly aggressive, lashing out at drug dealers and starting trouble with ex-girlfriends even as he considers a job offering from the Department of Homeland Security (who want to send him down to Columbia for some under-the-radar dirty work suiting his brutal skill set).

Less plot-driven than Training Day, Harsh Times is a more personal, character-centric effort for Ayer, and while it lacks the relentless intensity of the earlier film it mostly makes up for it with its sharply observed characterizations and sequences that simmer with nervous energy – he skillfully allows the lazy rhythms of Jim and Mike’s directionless trips around the city to flare up into violent confrontations throughout. Sure, you’ll know from frame one that the film will end up in bloody Taxi Driver-ish territory by the final reel, but there’s a realistic edge to the characters – especially Jim – that anchors Harsh Times in frightening believability.

Bale, as usual, is terrific in the lead role; he’s played his share of unhinged characters before (American Psycho, The Machinist, The Prestige, etc.), but Jim is an entirely different breed, lacking any kind of focus or clarity and taking out his aggressions sporadically at the slightest provocation. Also quite good is Rodriguez, whose ostensible “straight-man” role is more complex morally than Hawke’s rather Boy Scout-ish Training Day character. It’s pretty clear from the get-go that Jim is headed for trouble, but the film generates a lot of suspense as to just how far Mike is willing to follow him; Rodriguez does a terrific job of balancing his good-guy tendencies with his loyalty to his friend and capability to break the law as Jim does.

Altogether, the film offers a fascinating portrait of damaged characters in a burnt-out urban environment, one that Ayer knew firsthand and translates to the screen in ways that, at their best, bring to mind the work of Martin Scorsese, Spike Lee, the Hughes Brothers, et al. He’s yet to make a perfect film, but I think if he continues on this trajectory of urban crime dramas Ayer could at some point make the Taxi Driver or French Connection for our generation – though even if he gives up that particular tack after Street Kings, he’s displayed enough talent to make him a filmmaker worth following whatever he takes on.