“Adam-12” on steroids would be one way to describe “End of Watch,” a Los Angeles cop-on-the-beat saga, partially shot in the now-tiresome ultra-jerky “found footage” style, that recounts the route of two police partners driving their way to a doom-laden finale. David Ayer’s film is obviously aiming for a “Training Day” vibe (a picture Ayer also wrote), but despite good chemistry from Jake Gyllenhaal and Michael Pena as the squad car men in blue on volatile patrol, it falls short of the kind of emotional punch that would make it a special tour of duty.

The picture opens with a burst of speed, a sequence in which Ben Taylor (Gyllenhaal) and Mike Zavala (Pena) engage in a high-speed chase that ends with them taking out some gun-toting perps. We then shift to the locker room, where we’re told, direct-person style, that Taylor is shooting a “you are there” film for a class he’s taking with tiny person-mounted cameras through which we’ll witness a lot of what follows. That establishing scene also introduces the boys’ squad room nemesis, cynical Officer Van Hauser (David Harbour).

What follows is an episodic account of the duo’s trips through L.A.’s mean streets, concentrating on their search for a gang responsible for a series of drive-by shootings and their investigation—which happens to be connected to the drive-bys—of a drug ring. But there are also stops at a burning house, where the guys save a baby from the inferno before the firefighters can arrive, as well as at a decrepit place that’s been taken over by torturers (an especially grisly scene). And the partners answer an “officer down” call where they take the assailant into custody rather than killing him on the spot, though they might well have done so.

Those and other scenes are fairly grisly stuff, but there is some compensation in the guys’ macho banter, very unlike the stiff conversations Jack Webb used to pen for Reed and Malloy, which shows their easygoing camaraderie, and in the digressions that deal with their personal lives. Zavala is the married man with a pregnant wife (Natalie Martinez), while Taylor has connected with a petite young thing (Anna Kendrick), somewhat of a vicarious thrill-seeker, and is drawn to his weaponry in every sense.

“End of Watch” isn’t critical of its heroes; to the contrary, though they’re sometimes shown bending the rules, they’re careful not to break them, and their captain (Jamie Fitzsimmons) is apt to praise them rather than holler at them in the style of old-time TV shows. Taylor and Zavala are out to do good in a difficult and dangerous job, and the if the constant pressure leads them to be more than a bit rambunctious, that’s presented as an understandable part of the business. The other squad members—including female officers played by America Ferrera and Cody Horn—are also portrayed as dedicated, and even under more pressure than their male colleagues.

For much of its running-time, in fact “End of Watch” is a strong depiction of the bond the patrolmen have built over their years together, and the larger environment they work in (both back at the station and on the streets). The fundamental problem with it is that Ayer isn’t content with that: he feels the necessity to build to a big, explosive finale. So Taylor and Zavala’s intrusion into that drug case puts them in the cross-hairs of a drug cartel, and the result is a confrontation in a run-down housing development that’s staged like an urban mini-war. This is really playing the adrenaline card for a crowd that Ayer apparently believes wouldn’t be satisfied with something smaller, quieter but more truthful. The emotional effect he’s aiming for is clear—indeed, the ending rather beats you over the head with his tear-jerking message. But it could have been achieved in a simpler, less bombastic fashion—with a touch of irony, perhaps, that would have made it all the more affecting.

Still, one has to admire the energy of the picture, along with the strong lead performances, the excellent supporting cast (each member of which gets at least one scene in which to shine) and fine technical work from cinematographer Roman Vasyanov, editor Dody Dorn, production designer Devoran Herbert and art director Kevin Constant make the film. If only, as so often happens in today’s action films, this “Watch” didn’t have to end in a big, splashy splurge of violence that goes too far over the top to feel authentic. Much of Ayer’s picture has the feel of reality, but the last twenty minutes move into empty spectacle and heart-on-sleeve mawkishness. That’s a pity.