Entertainment

Cops! crooks! corruption!

Officer Doug Kennard was nicknamed “Jumbo.” He was a 6-foot-5, 250-pound former oil roughneck turned cop. He could grab someone on the top of his head with one hand and lift him into the air. He was not someone you’d want to meet in a dark alley.

Only, more than a few criminals did.

After World War II, a scourge of pickpocketing hit Los Angeles. Veterans returning from battle would disembark in town and spend a night before catching a bus or train to their hometowns. Exhausted, many took to hitting local movie theaters to catch some shut-eye.

That’s when the pickpockets moved in, robbing the servicemen of their valuables, as they slept.

The LAPD was determined to shut the thieves down, and sent in a squad to spot the criminals from the projection booth and corral them. Except they weren’t arrested. These cops had no interest in jails and trials. The pickpockets were instead dragged into an alley where Jumbo Kennard was waiting.

Jumbo would menace the unfortunate captive. He would pull out a gun and scream about what he was going to do to the thief. He would mention dead bodies. Other cops would pretend to hold Kennard back.

Finally, another officer would advise the pickpocket to get lost before something terrible happened. The thief would tear off down the alley, in the darkness, only to trip over a chain mysteriously strung across the opening and crash hard to the ground.

The result: No more pickpocketing at the theaters.

GOSLING AND STONE’S ON-SCREEN CHEMISTRY

This story is just one from the annals of the LAPD in the 1940s, a more lawless, corruption-heavy time vividly recalled in “Gangster Squad: Covert Cops, the Mob and the Battle for Los Angeles” by Paul Lieberman.

The book is the basis for Friday’s “Gangster Squad” movie, about a small, off-the-books unit of cops that was formed to take down mobsters in post-war Los Angeles using any means necessary.

“The cops essentially behave as badly as the criminals, because that is the only way to get to them,” says Josh Brolin, who plays Sgt. Jack O’Mara, a member of the squad.

This is no Hollywood fiction. O’Mara, Kennard (played by Robert Patrick) and the rest of the unit from the film did exist and often bent or ignored the law in their quest to restore order to LA’s streets.

“There was a bookie who ran a barber shop and he was trying to corrupt a beat cop,” Lieberman says. “So the deputy chief told them, ‘Head on down and teach this guy a lesson.’”

The squad smashed up the shop and forcibly shaved the barber’s head.

Going to extremes was necessary in order to wrest the city back from the violence and chaos created in large part by Mickey Cohen, a feared mobster who was born in Brooklyn. He was arrested for the first time at age 7 for running bootleg gin, and eventually became the right-hand man to Bugsy Siegel. (Cohen is played by Sean Penn in “Gangster Squad.”)

“He was the perfect gangster for Los Angeles, because both were obsessed with image,” Lieberman says. “Today, he’d have a reality TV show.”

“Cohen, in real life, was over the top,” says “Gangster Squad” producer Dan Lin. “He was funny, he loved talking to reporters and, in public, he really wanted to entertain people, as if he were one of the movie stars he was always trying to woo. Of course, in private, he was doing dark, evil things.”

Cohen had his own publicist, held court at local nightclubs, once posed in Life magazine and appeared on Mike Wallace’s talk show. He was said to never wear the same suit twice, and he and his crew often cruised the Sunset Strip in a trio of expensive Cadillacs.

Dragged before a Senate select committee on organized crime in 1950, Cohen — who survived several assassination attempts — was asked by Sen. Charles Tobey, “Is it not a fact that you live extravagantly, surrounded by violence?” to which Cohen replied, “Whaddya mean ‘surrounded by violence?’ . . . people are shooting at me.”

Arresting Cohen, however, was no joke to the gangster squad, and they weren’t going to let proper procedure or warrants stand in their way.

In one epic operation, the squad’s electronics man Con Keeler (played by Giovanni Ribisi) managed to bug Cohen’s Brentwood home, only to have the device discovered by his gardener. The squad tried again, sneaking under the heavily fortified abode and planting a listening device in his closet. Unfortunately, the wireless bug began interfering with Cohen’s expensive new toy: a television.

Cohen called the store to complain about the reception, and a repair team was dispatched. O’Mara and the squad intercepted the repairmen and sent one of their own on the visit to Cohen’s home. A new bug was secretly planted in the television, and the old bug was disabled, restoring Cohen’s reception. The mobster was so pleased, he tipped the repairmen lavishly.

“That’s how Mickey paid for his own bugging,” Lieberman says.

Keeler later used his surveillance expertise to help Jack Webb, the man behind TV’s “Dragnet.” Webb was in the process of divorcing singer Julie London, and feared she would take all his money. Webb asked Chief William Parker (played by Nick Nolte) for a favor, and Keeler was dispatched to bug London.

Other operations were more overt. Cohen, who was fond of taunting the cops, calling them the “stupid squad,” once sent the head of the unit a funeral wreath as a threat. The cops were dispatched to confront Cohen, tommy guns poking out of their overcoats.

One of the later additions to the squad was Sgt. Jerry Wooters (played by Ryan Gosling), a fun-loving rogue who was the opposite of O’Mara, the head usher at his church.

“He was a ladies’ man in his early life, so Ryan Gosling playing him is not a real stretch,” Lieberman says.

Wooters flew in WWII, and was shot down. While in the hospital, he flirted with dozens of nurses, keeping photos and letters from them for the rest of his life.

He later dated a stewardess and was known for throwing parties stocked with her pretty airline friends. He sometimes screened racy films that had been confiscated by the vice squad for police cadets, and during a Christmas party one year, he was discovered in the back room presiding over a craps game.

Lieberman says that Wooters had a thing for redheads, and in the movie, he romances auburn-haired Emma Stone, who plays an aspiring actress and mob moll.

Her character is a screenwriter’s invention, but the rest of the movie is generally faithful to history, illuminating a time when, as Lieberman writes, “truth was found not in the sunlight, but in the shadows, and justice found not in marble courthouses, but in the streets.”

reed.tucker@nypost.com