Once the preserve of horror, the found footage film has spread its wings to encompass that other staple Hollywood genre; the cop thriller.

It was only a matter of time; our TV screens have been clogged up for years with such police-friendly ‘reality’ shows as Cops and Police, Camera, Action. All the while, fictional cop shows have endeavoured to become ever more authentic (minus the fruitier language), with arguably the most successful example of recent times being the acclaimed Southland.

In one episode of Southland, a patrolman must deal with the ramifications of punching a member of the public after it is caught on camera and broadcast online. As the episode’s opening narration states, “it’s a new age – a video age. People are always watching us [the police]. Everywhere”.

Writer-director David Ayer addresses this “new age” head-on in End of Watch. LAPD officer Brian Taylor (Jake Gyllenhaal) is filming his day-to-day official activities for a project, to the annoyance of his partner and close friend Mike Zavala (Michael Peña). To assist with this Taylor fixes tiny cameras to each of their shirts to allow for first-person filming.

Following an arrest which turns up a stash of cash and a gold-plated AK-47 (“two of the major food groups – money and guns”, Taylor states), the two investigate a Mexican drug cartel. Although urged to let it go, Taylor persuades Zavala to stay the course, but little do they realise they’ve made themselves the cartel’s most wanted.

Ayer has made a speciality of hard-bitten cop dramas, from writing stints on the Oscar-winning Training Day (2001) and under-rated Dark Blue (2002), to penning and directing the less successful Street Kings (2008); all of which dealt with police corruption, something that’s absent in End of Watch. Here the hook is the first-person filming style, described by Ayer as being akin to “watching YouTube — where something in your mind tells you this is real”.

It’s an interesting notion that at times works very effectively, especially during an edge-of-the-seat scene where Taylor and Zavala enter a burning building to save some kids. However, Ayer undermines these moments of found footage (and, in turn, the whole film) by sprinkling traditionally filmed shots in along the way (including that now ubiquitous ‘soaring above skyscrapers’ shot). You’re never sure whether you’re watching ‘real’ footage or not, which has the effect of pulling you out of the film. To make matters more confusing, when the camera is attached to the front of a gun, End of Watch resembles a first-person shooter computer game.

When you strip away all the pseudo-realism and gimmicks, this is a good old-fashioned buddy movie, akin to Lethal Weapon, and it’s the hugely entertaining camaraderie between Gyllenhaal and Peña that really drives the film forward.

In his most high-profile role to date, Peña is magnetic. Sure, his character fits the Latino stereotype we’ve come to expect, all hot-blooded, street smart and full of attitude, but Peña is a smart enough actor not to overplay it and instead gives a raw and entirely believable performance.

Gyllenhaal is a hard actor to pin down, but is usually at his best when dialling it down in such films as Zodiac and Brokeback Mountain. Here he delivers the full range, from bug-eyed hot-shot to measured introspection and just about carries it off. He gives as good as he gets when playing opposite Peña and it’s in the scenes when they are riding in the patrol car where both actors bring their A-game and really ignite the film. Here the dialogue really fizzes in spite of its somewhat clichéd nature (the differences between white and Mexican culture).

Much like the over-rated Training Day, character development is sorely missing from End of Watch. Ayer deals in black and white simplicity here, chiefly in the way the Mexican cartel gang is portrayed. With absolutely no redeeming traits, we’re left to wait patiently until they can be chalked off. Indeed, when the shifty-eyed head honcho Big Evil responds to why he’s called that by stating “’cause my evil’s big”, it’s clear Ayer isn’t exactly straining himself to make his villians memorable.

By adopting the found footage approach, Ayer has delivered a fresh take on the police drama and in Gyllenhaal and Peña has found one of its most likeable partnerships. However, like much of the content on YouTube, End of Watch won’t stay long in the memory.