The cop genre has gone through numerous guises and iterations, but End of Watch represents a serious, sometimes gripping, occasionally humorous (but always human) addition to the genre, which succeeds despite some early creative wrong-footing.

No one could accuse director David Ayers of venturing out of his comfort zone much, and like his best films, 2006’s underrated Harsh Times and Training Day (which he scripted) End of Watch offers that similar two-hander set-up. Tonally however, the film has more in common with the former than the Denzel Washington-headliner.

Officer Taylor and Officer Zavala (Jake Gyllenhaal and Michael Peña, respectively) are two young police officers who patrol the hot and sweaty mean streets of (a vividly captured) South Central LA. They’re a tight unit, both on the force and in their lives outside of the workplace. Taylor takes centre stage at his partner’s daughter’s Quinceañera, while Zavala performs best man duties at Taylor wedding to girlfriend Janet (a tad underused Anna Kendrick). That bond is jeopardised when a routine police visit inadvertently finds them coming into close contact with a notorious Mexican cartel.

What begins as a hybrid of documentary-style filmmaking and the (increasingly overused) found footage device, at first, this threatens to be the film’s undoing. It almost out-Shields The Shield with its frenetic hand-held work, and Ayer’s decision to incorporate material filmed by the actors in character within all that is a jarring experience for the viewer. It’s clear his intentions for going down this route is to further peel back emotional layers, but it feels too much, and in truth, the film is powerful enough without it.

Fortunately, as events progress the extraneous footage ebbs away meaning the film’s greatest asset, the relationship between Gyllenhaal and Peña’s characters, is given the unobtrusive focus it deserves. The natural, brotherly banter between the pair forges a believable and indelible relationship, and this on-screen chemistry helps ramp up the tension when the two are engaged in a number of dramatic, life-threatening situations. There’s none of that seasoned cop teaching his young partner life lessons. These are two young men thrust into a frightening world who must rely on each other daily in order to survive. Both officers are in simpatico and the two actors do a terrific job of bringing a moving authenticity to this.

Ayer is currently in production on (of all things) yet another Schwarzenegger comeback vehicle, but on the strength of End of Watch it would appear he is much better suited to the type of riveting, small-scale character drama he establishes here. With a reputed budget totalling a meagre m (particularly impressive, given the talent attached) its money well spent.