Revealing mistake: As Jerry leaves Mrs. Brewster's bedroom, a mirror reflection shows the door opening a crack before he even touches the knob. (00:27:00)
Revealing mistake: When Jerry is dragging Charley across the bedroom by his neck, he turns around and slams him into a wall. It wouldn't be unreasonable to assume that once his head makes contact, the wall's gonna break somewhere. But notice how the wall is already cracked right above the classic convertible picture a split second before it should be (widescreen only). (00:29:05)
Revealing mistake: A string is visible pulling the rocking chair on Jerry's porch as Charley approaches the house. (01:14:20)
Revealing mistake: During the basement finale, lines can be seen suspending Jerry in the air when he lunges towards Peter and sends him crashing into some shelves stacked with glass bottles. (01:37:55)
Revealing mistake: When Charley stabs Dandridge in the hand with his pencil, he stabs the hand holding him by the neck. The depth of the wound on Dandridge's hand reveals that the pencil should have stabbed Charlie in his neck and given him a severe wound, if not kill him.
Revealing mistake: Charley stabs Jerry Dandridge in the hand with a pencil. Look closely as he removes it, you can see it comes out in an 'antenna' fashion with a sucker attached in the palm of his hand.
Revealing mistake: Near the end, when Peter stakes Jerry while he is lying in his coffin, it's visible that the stake is held under his armpit and not into his chest.
Revealing mistake: Look carefully when Chris Sarandon jumps through the stained glass window - you can see it is his stunt double and not him, plus the stunt double is wearing gray sneakers instead of gray dress shoes.
Answer: Peter's odd behavior at Jerry's house made Jerry suspicious. When he discovers the shard of the mirror on the ground he finds out why Peter was spooked: Jerry doesn't cast a reflection. Jerry then decided that Charley's friends must be dealt with. In Ed, Jerry sees something which would lead him to believe Ed would make a good servant. Jerry turns Ed into a vampire and sets him against Peter while he himself deals with Charley and Amy.
BaconIsMyBFF