“The” journalist? He is suspected of ordering the assassinations of quite a few journalists, political opponents, and former agents. The guy is a KGB/FSB thug. It’s standard operating procedures for someone like him. KGB/FSB people are also masters of deception.
Suspected, but who knows with all the intrigue. Corruption runs deep in Russian and former Russian territories. A wink and a nod and some lower down does it, and there is plausible deniability all around.
Anyhow what Trump has said doesn’t sound all that far from “Trust but verify.”