He’s New York’s “Bad Lieutenant.”

In four years, Port Authority Lt. Patric Mangieri has gone from hero cop of the Hudson to police pariah as his superiors try to drum him off the force for everything from an obstruction bust to allegedly trading “sexual favors” with a woman to get her off a drug rap.

Before his alleged antics recently came to light, the only public attention that Mangieri had ever received was good.

In the weeks after Chelsey “Sully” Sullenberger saved US Airways Flt. 1549 by safely crash-landing the jet in the Hudson River on Jan. 15, 2009, Mangieri was lauded for quickly racing from his post at the Lincoln Tunnel that day to help rescue passengers.

But nearly two years later, Mangieri — one of the highest-paid lawmen at the PA — was caught firing his department-issued gun at his home in suburban West Orange, NJ, the bizarre culmination of a love triangle gone bad, records show.

The incident then led to a months-long investigation that allegedly uncovered much more.

What probers found wasn’t pretty: misuse of official police records; repeatedly lying to cops and superiors even in the face of unassailable evidence of misconduct; misuse of PA equipment and computer systems, and the trading of “sexual favors” in return for letting the woman off on drug charges, according to the PA report.

Late last year, Magieri quietly copped a plea in New Jersey Superior Court to one count of obstruction and agreed to forfeit his right to hold public employment.

Mangieri is now suspended without pay, and the PA is trying to fire the 30-year police veteran — only months away from him reaching his full 20 years on the PAPD roster — to keep him from collecting his full pension.

Mangieri, 55, did not return calls and neither did his lawyers.

A married father of two, Mangieri came to the PA after nearly 13 years with the small police department in Orange, NJ, just outside of Newark.

At the PA, Mangieri’s base pay is listed at $125,000 a year. With overtime, he pulled down $195,000 in 2011, his last full year on the job..

Mild concerns about the cop had bubbled up before his heroics, sources told The Post.

Then a sergeant with a taste for expensive suits best described as “Mafia chic,” Mangieri was once taken to task for his odd taste in police-locker décor.

He kept a photo of the late Dapper Don, John Gotti taped inside his locker. The photo was removed after Mangieri’s bosses called him on the carpet.

But by the time of the Miracle on the Hudson rescue, Mangieri had been promoted to lieutenant, a coveted spot at the PA because of the tons of OT that come along with the rank.

Then, as with Harvey Keitel’s character in the flick “Bad Leiutenant,’’ Mangieri’s career started to unravel.

Mangieri was having an affair with a Madison Square Garden IT executive named Belinda Binkley, according to PA investigators, though he denied it later. He communicated with Binkley on PA computers and e-mail, and the affair led to a confrontation with a New Jersey man named Michal Deszcz, who had previously dated Binkley, the PA report said.

It was the appearance of Deszcz at Mangieri’s home that led to the middle-of-the-night gunplay that ultimately ended Mangieri’s career. No one was hurt in the incident.

Mangieri filed a bogus local police report that led cops to arrest Deszcz on false pretenses, according to authorities. He also ordered a PA subordinate to access Deszcz’s record on the national-crime database, the PA report said.

Deszcz and Binkley would not comment to The Post.

The gun incident led to dual investigations by the West Orange PD and the PA’s inspector general.

As part of the probe, investigators said, they found “paper copies of several sexually explicit e-mails” in Mangieri’s locker at the Lincoln Tunnel. The e-mails were allegedly between him and the female drug suspect.

“One of the e-mails described him as stopping to assist a female motorist … Upon realizing there was marijuana in the vehicle and after threatening to arrest the woman, he decided to let the woman go with a warning. Mangieri then describes the female as offering sexual favors in return for his act of kindness,” the PA report said.

Investigators also reported that Mangieri “used his Port Authority e-mail account to receive nude photographs of a female from his personal cell phone. The woman was subsequently identified as the same individual” who offered her services to the cop.

The PA is throwing the book at Mangieri, filing 26 charges against the lieutenant for allegedly violating everything from deadly-force regs to rules governing ethics, conduct and use of PA property and equipment.

philip.messing@nypost.com