Revealing mistake: All of the exterior shots of Jessica and Hagarty are wide shots with very obvious stand-ins. Jessica is thinner and younger, while short-haired Hagarty's double is younger, chubbier, and has long hair around the nape.
The Murder of Sherlock Holmes - S1-E1
Revealing mistake: In part 2 of the episode, when Jessica is mugged, Angela Lansbury is replaced with a younger and thinner stunt double twice: when she runs away and when she protects herself against the wall.
Revealing mistake: When Jessica rides on the motorcycle, one can see it's a much younger and thinner stunt double who doesn't resemble Angela Lansbury.
Revealing mistake: After Denton falls off his horse, Jessica arrives and jumps off hers. Her stand-in is a much younger and thinner woman who looks nothing like Angela Lansbury.
Death Takes a Curtain Call - S1-E9
Continuity mistake: The way the sheriff hands over the phone to Major Anatole Karzofman differs between the first and second shot, with the handset turning 180ยบ.
Death Takes a Curtain Call - S1-E9
Continuity mistake: When Jessica questions Eddington, he has his glasses on. An instant shot later, they're on his hand.
Death Takes a Curtain Call - S1-E9
Visible crew/equipment: When Jessica and the Russians exit the theatre, the whole filming crew and cameras are reflected on the car's fender.
Death Takes a Curtain Call - S1-E9
Revealing mistake: When the cops arrive at supper time at Jessica's door, the background is a blatant painted backdrop. (00:31:45)
Funeral at Fifty-Mile - S1-E22
Continuity mistake: When Jessica walks from the house to the barn at the end, she is wearing knee high brown boots. By the time she reaches the barn they have been replaced with court shoes.
Revealing mistake: When the first scene at Emma's hideaway was shown, obviously the two characters Emma and Jessica were filmed seperately on the couch and then the film was put together (as both are played by Angela Lansbury). However Jessica did a lot of moving while she was talking, so Emma was looking straight across at where she had been, despite her bending down while she talked.
Audio problem: When singing "Goodbye little yellow bird" Emma blows a kiss to Oliver offstage, but she is still singing the song when she is blowing the kiss. Although it's possible she was pretending as it was part of the act, her voice wasn't even muffled by her hand.
Continuity mistake: When Emma was almost hit by a car she jumped up onto the edge of the wall and then back down onto the floor. When she landed she was facing the theatre door, but when Oliver came of the door and the shot changed, she was facing away from the wall. This happened in the transition from stunt person to Angela.
Tinker, Tailor, Liar, Thief - S8-E15
Revealing mistake: In the second close up shot of Nigel Atkins lying dead, after Jessica drops her Harrod's bag in the chair, it is obvious he is still alive as you can see his pulse on the side of his neck.
Factual error: At the end of the episode after Wayne is shot, there is a brief shot of the outside of the hospital where he has been taken. The sign outside the hospital says Dalesboro, Ohio. Why would someone shot in coastal Maine end up in a hospital in Ohio?
Deadly Lady - S1-E2
Revealing mistake: When Howard Duff's two daughters enter the police station to identify his body, the cop pulls back the blanket. Howard's eyelids are moving even though he is supposed to be dead.
The Corpse Flew First Class - S3-E12
Factual error: As the airplane is coming in to land at Heathrow, there is an establishing shot of the wheels down, and in the background there are cars on the road, but driving on the right, wrong for the UK.
One Good Bid Deserves a Murder - S2-E17
Continuity mistake: The first time Jessica is shown asking for her room number, she asks for room 812. Later in the episode she asks for room 810.
The Murder of Sherlock Holmes - S1-E1
Continuity mistake: When Jessica's publisher at the beginning of the party holds her hand and kisses it, he is holding her hand in different ways in the separate shots. (00:18:20)
The Murder of Sherlock Holmes - S1-E1
Continuity mistake: Mr. Giles holds the telephone as he interrogates the private eye, who answers in a rather defiant way to the threat of "the local constable" getting involved. So Giles puts the receiver down, but notice that in the first shot he is passing it from the right to the left hand. In the close-up it is the right hand to hang up, though. (00:23:15)
The Murder of Sherlock Holmes - S1-E1
Continuity mistake: During the scene at the train station, Jessica's nephew introduces to her Kitt Donovan from the publishing company. Just as he says "in public relations", a man pops in the foreground - it is an extra that walks out of the rail car. In the reverse shot that follows, the same extra is only then coming out of the train. (00:09:35)
Chosen answer: This is the very reason my brother and I used to jokingly call the show, "Murder, She Caused." It's amazing she was ever on anyone's guest list for a party, given the likelihood someone would end up deceased. As to your question, most of the time, Jessica Fletcher would have had an air-tight alibi, as she was in a room full of people, or her whereabouts were accounted for when a murder occurred elsewhere. It also seems to me that there were episodes where she, purely with respect to opportunity, could have been a suspect. I believe she even acknowledged that as a logical possibility from time to time, even though she knew, of course, she was not the killer. However, the investigation would obviously rule out the possibility of her involvement, eventually.
Michael Albert