Crime always occurs because there is a money motive in it. I think if I had to sell bitcoins to someone offline then I would sell small amounts of bitcoins, because it is too dangerous. For large amounts, maybe online trading is better, and if we use a trusted exchange it is also safe
If there is money there is a possibility of being attacked by terrorists. Be it Bitcoin or fiat money, this can be the case. However, terrorists are more attracted to crypto users because of the potential for large sums of money. There is no alternative to raising awareness personally to avoid any such untoward incident. Offline Bitcoin transactions is completely risky. Maybe this is a trap through which a Bitcoin seller can be a victim by those terrorists. Online platforms must be used for Bitcoin transactions and it is completely safe and secure. It is safe to use Binance's P2P service to avoid such problems.