Tucked away between two monolithic skyscrapers on a short Manhattan street quaintly named “Old Slip” is a place that honors our heritage as police officers. It is the New York City Police Museum, where you can discover what makes our members “The Finest” and how the lives and roles of police officers over the centuries have changed.

Here you can steep yourself in the rich history of the nation’s greatest police force, have your picture taken in a jail cell or stand in front of a height indicator board for your own “mug shot.” Stepping across the threshold is to step into a time machine. If you enjoy police memorabilia like antique shields, police equipment of yesteryear, a policewoman’s uniform with regulation high heels and lipstick, vintage vehicles and much more, then a visit to this museum is a must for you and the family.

The museum’s first and most important mission, according to its director Michael Cronin (a former NYPD detective), is “to educate the public about the important work the NYPD does.” But the museum’s heart and soul, says Cronin, is the Hall of Heroes, where the shields of police officers who died in the line of duty reside in a display of perpetual respect. Visiting that room, with its more than 600 shields and nameplates, is a stark reminder of what this job is about. On another somber note, there’s also a display of artifacts — including police gear — removed from the smoldering wreckage of 9/11.

But don’t get me wrong — this can be a fun place. Where else can you see Al Capone’s Thompson submachine gun, more popularly known as a tommy-gun, and Willie Sutton’s burglar tools? Sutton, you might recall, was a very active stick-up man who, when asked why he stole from banks, responded, “Because that’s where the money is.”

The museum has been around in one form or another for 75 years, but this is the first time it’s been housed in a truly historic police building.

Today it’s in a fortress-like building built between 1909 and 1911 that served for 62 years as the home of the old First Precinct. In 1973, the department merged the First and Fourth Precincts into today’s First Precinct on Ericcson Place.

But it’s hard to deny the feeling that this building was intended one day to house this museum. Director Cronin affectionately calls the place “the NYPD’s attic,” an apt description for this repository of the artifacts and curiosities of the men and women who policed the city from the time when it was the early Dutch settlement of New Amsterdam, through the days of reform Police Commissioner Theodore Roosevelt and right up to the present.

There are three floors of exhibits. On the first floor, you experience the past: the earliest uniforms, badges, weapons, communications gear — everything from the ratchets of the 1600’s to early-20th-Century police radios. Here you’ll also see a 1972 police-green Plymouth Fury I with the silver-bullet-style siren, and an early police motorcycle.

The second floor reflects the job today, with exhibits devoted to various special units and information about the former Transit and Housing Police Departments. The museum’s fascinating weapons collection is also displayed on the second floor (including Capone’s gun and the Sutton’s burglar’s tools). The third level is the “tribute” floor, with the 9/11 exhibit and Hall of Heroes.

The NYPD can trace its roots to 1625, when the first dedicated law enforcement officer in America, Johann Lampo, served as the “schout fiscal” or sheriff’s attorney for the colony. There’s an old argument between New York and Boston about which has the oldest police force. A visit to this museum proves that New York does.

The museum also offers, at a very modest fee, a genealogy service to multi-generational police families. Stored in this “attic’s” attic are some 70,000 identification photos of MOS from the 1880s through the 1970s. Armed with just a sergeant’s shield number and a name, the museum was able to recover a photo and record of service for Sergeant Albert J. O’Leary, father of PBA Communications Director Al O’Leary who recently visited the museum.

From the “Index of Members of Force” card we were able to determine that Sgt. O’Leary came on the job on 9-21-1946 and was promoted to sergeant on 10-2-1960 on special order #251. The card also indicates that he retired from the job on 9-19-1966 on special order #201. So if your family has several generations of NYPD members and you’d like information about their service and a copy of the officer’s photo, the NYPD Police Museum genealogy service is perfect for you.

The Museum is open Tuesday through Saturday from 1000 hours to 1700 hours and on Sundays from 1100 hours to 1700 hours. Admission is free for police officers and their families and there is a suggested donation for others. And don’t forget to visit the museum store where you can get police gear — hats, shirts, books, toys and more — for every member of the family. For more information, log onto www.nycpolicemuseum.org, where you can also learn how to support the museum by becoming a member, making a donation, or participating in fun and interesting events.