UPDATE: Donald Trump has said he's considering suing the author of the original tweet (see below).
On the one hand, perhaps an American could be excused for not knowing two of Britain's biggest serial-killers but on the other, maybe Donald Trump should be a bit less blasé when communicating to 2.7 million people.
Also, the Twitter handle '@feckhead' should always ring alarm bells.
The man with the eternally glorious hair and distinctly less glorious opinions on pretty much everything retweeted a 'fan' who said he'd been a big inspiration to his deceased parents.
Only it was a massive lie. The picture attached is actually of those not-so-nice serial-killers Fred and Rose West.
But credit where credit's due, Trump's heart was in the right place.
Here's Trump's latest tweet...