He robs him.
Then the story gets worse.
After the witness jumps down on the track to steal the man's valuables, he climbs back up on the platform and leaves his victim to be hit by a train.
The man survived, but was seriously injured and had to amputate half his left foot, Sweden's TV3 channel reported.
Swedish police now hope that surveillance camera footage of the disturbing incident at a Stockholm subway station early Sunday will help them find and arrest the unscrupulous thief.
Police said Thursday they have received several tips after the video was shown on TV3 this week on Sweden's equivalent to "America's Most Wanted."
The thief had short, dark hair and was wearing a blue jacket and dark pants. He was described as being between 35 and 40 years old and about 5-foot-9 (175 centimeters).
He calmly walked out of the subway station, waving to the ticket vendor, as a train ran over the victim on the tracks below.