Ah, right, then I misremembered that completely. Human memory is fallible, mine just more so :D I wonder if we'll ever get a more definite answer – it could be Engström, but I wouldn't exactly bet on those odds. I sort of doubt it since it's been so long and it's not like you haven't been trying, but who knows? What do you figure?
No worries, the thing about Engström was that his story kept changing over time, but the time he punched out was one of the few things that could be verified. If it was because he was hiding something or because he was a troubled alcoholic who wanted to appear to have a bigger role in the Swedish crime of the century we may never find out. I think the chances of us ever knowing for sure who did it are slim, and if it was a lone killer we will probably never know. If it was a conspiracy there’s always a chance that there’s a paper trail that will one day be discovered, but to me that doesn’t appear to be the case. Palme had a lot of domestic haters both left and right, the Täby moderates allegedly had a dartboard with his face on it in their offices at the time, and in the 1975 book by marxist crime writers Sjöwall/Wahlöö the prime minister is gleefully murdered by a young woman that they describe in heroic terms. No wonder the investigation contains 90 000 names by now.