Jake Gyllenhaal and Michael Pena play partners against crime in the gritty police drama "End of Watch," writer/director David Ayer's good-cop foil to his bad-cop "Training Day" (2001) script. While patrolling the meanest streets in Los Angeles, the officers discover a dirty little secret, which puts them square in the cross-hairs of a violent drug cartel. We know "EOW" is going to be an alarmingly authentic ride-along through the savage depths of south central, but here are five facts about the film you may not know.

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1. To prepare for their roles, Gyllenhaal and Pena spent five months training with the Los Angeles Police Department, while going on upwards of 40 ride-alongs. As Gyllenhaal explains to Moviefone: "We went on ride-alongs for five months, two to three times a week with the LAPD and sheriff's department and Inglewood PD. We would work with them from about 4:00 p.m. to about four or five in the morning. Then we did tactical training about two or three times a week with live ammunition and training exercises, then fight training almost every morning with Dave Ayer's best friend, who has a dojo, getting the crap beat out of us by 14 to 20-year-old kids."

Watch 'End of Watch' Clip: Coffee

2. Apparently, all that training and time spent with the force wasn't enough to full capture the necessary authenticity. No, the cast had to go one step further. How's this for commitment? Gyllenhaal, Pena, and actresses Cody Horn and "Ugly Betty's" America Ferrera (who both play cops) all agreed to get tased! Since being tased is part of the training to become a police officer, the actors were asked if they wanted to participate. "We all decided that we thought it would be sort of a semi-bonding experience. ... When we had a choice between pepper spray and being tased, we were all told by the professionals that tasing was probably the preference because pepper spray lasts for a long time after. And a tase is done in moments. So we decided to go for quick and painful," Gyllenhaal told The Hollywood Reporter. Though the price may have been painfully steep, the bonding seems to have worked, as exemplified in the clip above.

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3. All the hard worked paid off though, as Gyllenhaal morphed into a cop so believably that he duped actual cops into thinking he was one of them. "Cops in LA will do a hand sign with four fingers to say 'everything's good.' Jake threw a 'Code Four' at some LAPD cops rolling by and they threw a 'Code Four' back. I don't think they had any idea it was Jake Gyllenhaal!" Ayer divulged to Yahoo! Movies.

Watch the 'End of Watch' theatrical trailer...

4. With such thorough preparation, the cast and crew zipped through principal shooting in just 22 days. As director, Ayers wanted to create frenetic and visceral imagery that puts the viewer smack dab in the front seat of a cop car. To do so, no less than four cameras were rolling at all times, capturing virtually all 360 degrees of the action. Ayers shot much of the footage from a first person point of view, while employing unorthodox cameras to tell the story, including cell phone cameras, security cameras, and clunky first-person rigs mounted to both Gyllenhaal and Pena. "[Ayer] strapped these cameras onto us. He built these weird contraptions, and I'm like the Mexican Robocop, trying to keep Jake in frame." said Pena during the EOW panel at Comic Con 2012. The theatrical trailer above shows plenty of evidence of Ayer's frenetic POV style.