Carney only puts one picture of Jennifer in the envelope to be delivered to the Tatler office, and he licks the flap to seal it. When the envelope is opened at the Tatler office, he loosens the clasp and takes out several pictures.
Jonathan asks Jennifer to call the police as he leaves to pursue the killer. However the killer cut the phone line in the earlier scene while the Hart's were taking, which was the reason Jonathan had rushed back home.
A yellow vehicle driving behind them disappears, with no opportunity to turn off.
As Jennifer, Stefanie Powers keeps her fingernails rather short. In the closeup of Jennifer holding a newspaper, the fingernails are much longer.
When Jonathan and Jennifer are trying to figure out the murders, they are listening to a tape supposedly dictated by Robert at the time of Louise's murder. Jennifer mentions she can hear chimes in the background, but when Robert is seen making a call, the chimes are heard after he hangs up the receiver.
When Laura is telling Mr. Wallace, Jonathan and Jennifer about Evelyn's death, she says, 'why would she be wearing her coat to bed?' But in the previous scene, seconds before the murder, the coat is no-where to be seen.
Right after the police tell Jennifer to stay home, Jonathan leaves Jennifer and Max there, when Max could have run the errand and Jonathan could have stayed home.
Jonathan is a gentleman and would have stood up when an older woman walked into the room.