This is actually reasonably funny, although in incredibly poor taste.
In the UK we have, at the moment, a big thing about paedophiles (Americans, omit the a). It's got to the point where people attacked the home of a paediatrician - yes, they were THAT stupid. So this case is MASSIVE.
So anyway, these two girls went missing. They turned up two days later dead, their bodies naked, burned, dumped in a ditch and partially eaten by animals.
The investigation lead to the school caretaker (Ian Huntley) and his wife (Maxine Carr) and they are currently on trial for the murders.
Carr, it turns out, provided a fake alibi for Huntley, by saying she was in the bath when the girls called round at his house. She was in fact 70 miles away in Grimsby at the time. She provided the alibi because Huntley was previously accused of indecent assault - falsely it turned out. She is being tried for "perverting the course of justice".
The prosecution claim that the girls came round Huntley's, he kidnapped and raped them (he was found to have washed his duvet cover AND duvet... Duh!), killed them, then put the bodies into the back of his car (forensics), cut their clothes off (forensics), dumped and burned their bodies (forensics).
He claims that one of the girls had a nosebleed in his bathrooom. She fell into the bath, banged her head and drowned. The other girl screamed, so he panicked, covered her mouth up, suffocating her (he admits her accidental murder) and THEN put their bodies in his car blah blah blah. If it wasn't for him washing his duvet (he'd never used a washing machine before and didn't have the faintest clue how to use one, or what to wash), this would actually be plausible - who knows what we do when we panic? - but even Carr thought he'd had sex with another woman when she found out.
So anyway. That long-winded prose explains the extreme poor taste of the joke, but it is at least vaguely funny, if you know who the people are and don't have any young children. I laughed, a bit...