(at around 51 mins) When Andy is walking to the boathouse to deliver the make-up box to Rollie, there is a shot of a girl on roller skates in a blue print blouse skating behind her. In the next shot, the skater is behind the cop trailing Andy. In the very next shot, the skater is way ahead in the distance in front of Andy.
In Tyler's apartment, when Tyler offers Lipton coffee, the pot is brewing and is over half full. In next shot, when Tyler goes to pour the coffee, the pot is still brewing but is only about 1/8th full.
As Defranco dies, his neck tie lies to his left, touching his trousers. Col. Mason removes the key from cross/pendent, and drops it on Defranco's chest. It lands on the tie. When McCarthy enters the room to check on the body, Defranco's shirt is opened wider, the necklace is moved, and the necktie is splayed, one end touching the floor, the other across his chest.
The uniforms worn by the New York State Police at Mason's mansion and the morgue are their dress blouses and are only worn for special ceremonies such as funerals, parades and awards and are never worn on patrol.
The goof items below may give away important plot points.
(at around 43 mins) When McCarthy is in bed and gets the call regarding the murder of Ellen at Tyler's apartment, he reaches for the phone and knocks a bowl of peanut shells on the floor that are next to the phone, when he is finished on the phone he hangs it up, and the bowl of peanut shells is back on the table.
(at around 41 mins) When Rollie moves Ellen from the floor to the bed after she has been shot, there is no blood or stain on the floor. Her injury was fatal, thus there should have been a large amount of blood on the floor.