The maniac gunman who killed at least five people at a Midtown office building on Monday evening was identified as a 27-year-old Las Vegas man, according to law enforcement sources. Shane Tamura was named by sources as the shooter who stormed 345 Park Avenue, a swanky 44-floor building and opened fire, killing one police officer and at least four civilians. The number of injured was expected to grow, the sources said.

Shane Tamura was identified as the deranged gunman in Monday’s deadly shooting.

A photo obtained by The Post showed he had a concealed firearms permit from Las Vegas with a 2027 expiration date.

The shooter was captured on surveillance footage strolling into the skyscraper with an assault rifle at around 6:30 p.m., just around evening rush hour.

Sources said he was found dead of a self-inflicted gunshot wound on the 33rd floor.

He sparked panic throughout the glossy tower that houses the NFL headquarters, Blackstone and other Big Apple companies.

Smears of blood were seen on the assault rifle Tamura used during his deadly rampage, according to a photo obtained by The Post.

Tamura had been a stand-out running back at Granada Hills Charter High School in California, according to an old interview he did with a local news outlet.

During the post-game interview, Tamura appeared soft spoken while discussing touchdowns he had scored that evening.

Sources said he was found dead of a self-inflicted gunshot wound on the 33rd floor.

It’s believed he acted alone, NYPD Commissioner Jessica Tisch said in a social media post.

Witnesses described mass panic as gunfire erupted.

“I was at work and this guy came in with an assault rifle and started shooting,” one man said. “I was in the lobby at work.”