It’s almost impossible to imagine an action movie without cops. Just think of an action movie right now. Did you think of "Die Hard?" "The Bourne Identity?" What about "The Terminator?"

See? Law enforcement almost entirely dominates the action movie genre, and Hollywood's portrayal of police and detectives in movies has been the focus of many a coffee shop discussion, pop-culture study and criminal justice blog article.

But how realistic are cop movies? To find out, we talked to a real, live Los Angeles police officer to get some feedback. Officer John Doe (fortunately not his real name) offered his input on these five famous scenes from classic cop movies, and how each might compare to real life. Now pass us another clip, please.

Scene 1: Lethal Weapon, the drug bust

In this scene, Mel Gibson is posing as the buyer in a drug bust. First he makes fun of the dealers by offering them $100 for the entire shipment. They get angry, so he pulls out a gun, tosses his badge onto the table and stands there grinning. Suddenly one of the dealers’ hidden henchmen starts firing and everyone scatters. A shootout ensues, and by the time Mel's backup arrives, one of the dealers has grabbed him and is holding him hostage. Naturally, Mel gets out of the situation by flipping out and head butting the guy.

The real deal: "It all depends on your plan and how you're going to execute it," officer Doe said, already pointing out one of Mel's oversights -- a plan. "First of all, we always wait for backup. They'd be right around the corner." This simple difference, predictably, makes Mel's seat-of-his-pants operation look like a flying circus.

Scene 2: Dirty Harry, the speech scene

Clint Eastwood is in a coffee shop when he witnesses a bank being robbed across the street. First he calls for backup, but once the alarm goes off and the robbers start coming out guns blazing, he decides to go after them himself. He shoots a few of them, then gets one on the ground. The guy is reaching for his gun, but Clint stops him by delivering his famous "do you feel lucky" speech. The guy gives up his gun just as backup arrives.

The real deal: A situation can realistically start out like this, Doe says, but there would be one slight difference. "If they start shooting, I'm going to be looking for cover," he said. I'm not going to try to be the hero and start firing at everyone until backup comes ... I want to go home at night." Fortunately for Eastwood, he didn't have to worry about that, since in his corner was one of the cardinal rules of action movie bad guys: They always miss.

Scene 3: Die Hard, Willis vs. cop

New York cop Bruce Willis has set off the fire alarm and radioed the LAPD about the hostage situation in the building he is hiding in. A single officer in a patrol car shows up to investigate, but finding nothing unusual, he starts to drive away again. To get the officer's attention, Bruce drops a dead terrorist onto the cop car from a few floors up, then opens fire on the officer's car with an automatic rifle, riddling it with holes and sending the officer into a panic. The officer frantically radios for reinforcements. Mission accomplished.

The real deal: Is this situation realistic? "Yes and no," says Officer Doe. "I would do whatever I had to to get that guy's attention. If I had to drop a dead body over, I'd drop a dead body over." But fortunately, it probably wouldn't come to that given the reality of the other factor in the equation: the officer in the parking lot. "It would depend on what the call that came out was, but I would have a little more than one unit there," Doe said. Even when they don't directly receive the call, he says, other officers tend to show up in those situations, so it's unlikely Bruce Willis would have to resort to barbaric displays to get attention. "And I'm going to exhaust all means necessary [to discover the problem] before I leave," Doe said. That's probably good for car maintenance, too.

Scene 4: The Departed, the rooftop arrest

Leo DiCaprio (an undercover cop posing as a criminal) has lured police officer Matt Damon to a rooftop, where he tries to singlehandedly arrest him for being a police mole. But as he is arresting Damon, another officer shows up. Unaware that DiCaprio is a cop, the officer holds him at gunpoint, demanding that he release Damon. The tension mounts as DiCaprio, using Damon as a human shield, moves to bring him down the elevator. They make it safely into the elevator away from the armed officer, and DiCaprio relaxes. But just as the elevator door opens again, he is shot by another police mole who has followed him there. Damon goes free.

The real deal: There are a couple of things wrong with this situation, Officer Doe points out. First, DiCapprio's case isn't quite air tight yet. "The officer would have to present some good, hard evidence that proves that he's a mole," Doe said. If we recall the movie, DiCapprio has thus far kept his evidence from the department. The other problem is DiCapprio's idea to meet Damon alone. "One officer would not just arrest him, you know, there'd be other officers involved," Doe said. "If he's dangerous, it could be a lot." This spells bad news for DiCapprio, who has no backup. Damon does. The rest, as we can see, worked itself out as expected.

Scene 5: Point Break, the skydive / robbery

Undercover cop Keanu Reeves thinks he has been discovered by the bank robbers he is trying to infiltrate, but he isn't sure. Before he has time to leave his place, the robbers (a bunch of adrenaline junkies) show up at the door and invite him on a secret mission. Deciding to keep playing along in case he's wrong, he agrees to go with them. They bring him on a skydiving trip, during which time one of their henchmen captures Keanu's girlfriend. Now holding his girl hostage, the robbers force Keanu to participate in a robbery with them, which he does to save the girl. He doesn’t get a fair cut.

The real deal: As is typical of most Keanu movies, this one is way out there. "I don't think that would happen," Officer Doe says. It seems Keanu's play-along-and-see-how-it-goes tactic is a bit outside of standard procedure, especially when it comes to helping with a robbery. "I would notify people at my department and we'd do what we could," Doe said. "Because if something went down and someone got shot, I'd be responsible."

Of course it's hard to compare police movies with reality anyway, simply because without directors on hand to control real life, it's difficult for officers to know what will happen in any given scenario. Whether an officer decides to radio for backup or grab the nearest AK-47 depends on the details of the situation. "We can play what-if all day, but what it comes down to is you never know what a situation will be like, so you just have to rely on your training," Doe points out. And dammit, if Clint Eastwood's training tells him to play Russian roulette with a criminal's face, that's exactly what he should do.