A Czech man decided for a more radical way: BBC NEWS | Europe | Diplomat shot dead in Prague
The best on it is (and I discovered it only now when looking for an English news link about it), that in 60's - 70's the old moron was a double spy for CIA and the communist Czech secret police STB. He even managed to pass CIA's polygraph tests without them having a doubt. One must wonder what CIA's tests are worth of if a moron falling for a Nigerian scam (and shooting an ambassador because of it) can fool them. See more info about it here: https://antipolygraph.org/cgi-bin/forums/YaBB.pl?num=1131015880
However, it looks like his old contacts from the communist regime are still working fine in recent democratic Czech Republic. That's no wonder, because courts, police, parliament, and all governmental agencies are still infested with former communists and STB agents. So the man was first completely freed by the court, then (after protests from Nigeria) he was sentenced to 8 years, which was promptly reduced to 5 years. However, he never started the sentence and was freed by a judge because of serious health problems. Well, being a medicine doctor and a crook himself who managed to fool the CIA, it was certainly not difficult for him to fool judges about his health too (if it was needed at all - the communist connections may have worked better and this was just an excuse for the public): BBC NEWS | Europe | Court frees Czech diplomat killer
Well, I believe Pacovsky deserved a severe sentence - in fact a double sentence - first for his stupidity to fall for the scam, and second for the murder. On the other hand, the Nigerian government does very little against the scammers, and in fact they are suspected being part of the scam industry. I saw once statistics about the Nigerian scams, and the number of cases and involved volumes of money were absolutely unbelievable - I do not remember exactly but the article claimed the scam being one of the most important source of income for Nigeria (I think it claimed the second or even the first place).