The killer vanished into the night, leaving a cold trail behind him.

FORBES: Halloween Murder of Trick-or-Treater Still Unsolved 17 Years Later

He was tracked to Jordan and then, possibly, Syria before his trail went cold.

FORBES: Kidnap Inc.

After his indictment the FBI followed him through Illinois, Indiana and out west to Arizona, but the trail ran cold.

BBC: Eric Justin Toth

Police, sheriff's deputies and federal agents swarmed into the area, working through a weekend blizzard, but the trail was cold for days.

CNN: STORY HIGHLIGHTS

"There are multiple jurisdictions and unless it's an ongoing crime that uses the same path all the time, the trail goes cold quickly, " Spafford said.

CNN: Twitter message could be cyber criminal at work

But it also demanded the very best of our people -- the highest level of creativity, dedication, teamwork, analysis, and just sheer, dogged determination to never give up when the trail went cold.

WHITEHOUSE: President Obama Thanks the Intelligence Community

Still, the trail remained cold.

WSJ: U.S. Rolled Dice in bin Laden Raid

The trail went cold.

ECONOMIST: A horrible case shows the need for competent policing