MOSCOW — The assassination bore all the hallmarks of yet another contract killing carried out in the murky shadows of the conflict pitting Russia against Ukraine.

A photo of the victim, a dissident Russian journalist, showed him lying face down Tuesday in a vermilion pool of his own blood. He was found by his wife, and died on the way to a hospital from multiple gunshot wounds to the back, said the police in Kiev, Ukraine’s capital.

Then on Wednesday, the journalist, Arkady Babchenko, to all appearances very much alive, walked into a news conference that Ukrainian security officials had called to discuss his “murder.”

“First of all, I would like to apologize that all of you had to live through this, because I know the horrible feeling when you have to bury your colleagues,” Mr. Babchenko told stunned reporters after the gasps died down. “Separately, I want to apologize to my wife for all the hell she had to go through.”