There have to be some stories out there where a person claims that they didn’t commit a murder and they can prove it…because at the time of the death they were committing another, nearly as heinous crime which can be substantiated as happening concurrently.
What’s the worst crime in fiction (or hell, real life) used as an alibi for murder? Rape? Child abuse? Physical assault? War crimes?
At the back of my mind I have the vaguest memory of someone claiming that they couldn’t have committed the murder because they were raping someone at the time - and the fact that she kept the baby proved how he spent the night in question. Maybe an episode of Law and Order?
In one Sherlock Holmes story, the obvious suspect for a murder (well, obvious to anyone who wasn’t a criminology genius) was exonerated by virtue of being arrested in New York eight hours after the crime in England (and of course it’s impossible to cross the Atlantic that quickly). But I think the New York arrest was just for robbery, which isn’t a very tough bar to clear.
A variation on the theme: In an episode of Hill Street Blues, a loan shark turned state’s witness in another case once he was given immunity for any crimes that came out during his testimony. When asked “How can you remember the date so clearly?” he replied “Because that was the day I killed Harry Garibaldi.”
In Iain Pears’ Instance of the Fingerpost the accused murderer was in fact committing a crime at the time of the murder, but
can’t use it in court, because the crime was “holding Nonconformist Church meetings” and if she makes that her alibi, she puts the entire rest of her church in the pot
I’m sure that the short fiction of Henry Slesar includes this scenario. I recall a story, maybe by him, maybe by someone else, where a man is convicted of murdering someone but can’t use his alibi because “at the time of the crime I was similarly engaged…with my wife.”
The plot in a COLUMBO episode – “Publish or Perish” – had Jack Cassidy, the man with the most punchable face ever seen, establish his alibi by smashing his car into someone else’s before getting locked up for drunkenness.
He hams it up like mad, since the point is for (a) the bartender to remember the irritating loudmouth who was boozing it up and for (b) it to be plausible that he was so drunk that, when asked where he was during the murder, apparently doesn’t even recall smashing into that vehicle – because the best alibi is one the insult-slinger clearly didn’t set up, to the point where he honestly doesn’t seem to realize he has it.
One of James Cagney’s better movies, White Heat, has something like this as a plot point. Cody Jarrett confesses to a crime actually committed by one of his associates, in order to give himself an alibi for the more serous crime he actually committed at the same time in a different state.
Depends on your definition of “heinous”, and it’s also subverted, but…
In the Star Trek: Deep Space Nine episode “Necessary Evil”, we see flashbacks of the Cardassian occupation of the station (and the planet, for that matter). Kira Nerys is a suspect in the murder of Vaatrik, a Bajoran collaborator. She finally admits to Odo, the person investigating the case, that she couldn’t have committed the murder because she was planting a bomb at the ore processor at the time. (She was part of the Bajoran resistance against the Cardassians). Kira would have been executed if he’d told this to station commander Gul Dukat. Odo’s only investigating the murder, so he lets her go.
In the present-day, with the station now jointly administered by the Federation, Odo finds some intriguing new evidence. Kira admits that she lied about her alibi-- Vaatrik was her responsibility, and one of her cellmates blew up the ore processor. She hadn’t gone into Vaatrik’s shop with the intention of killing him, however-- she was looking for a list of collaborators which she never found. Vaatrik caught her breaking in, and Kira had to kill him to avoid discovery.