The T.P.F. Insignia on Garrett Morris' collar is for "Tactical Patrol Force", an N.Y.P.D. unit formed in 1959.
One of the burglars looks into a sack taken out of the safe and exclaims in delight, "Double eagles!" The double eagle is a $20 gold coin, no longer made. One of them is now worth several thousand dollars.
The apartment building in the movie is in reality the Convent of the Sacred Heart, whose address is indeed the one given as that of the building, 1 East 91st Street.
The first major motion picture for Christopher Walken (he gets an "And Introducing" credit).