In addition, there was a timing device that may help link the bomb to its makers. The device used is said to be more sophisticated than was at first believed. CNN has learned that investigators have a number of videotapes and snapshots and are studying pictures from surveillance cameras that ring the park. They were reportedly acting rowdy and drawing attention to themselves. In the days before the bombing, federal officials told CNN that a group of skinheads with a reputation for violence was being monitored.
Officials now say that is one of the leads being pursued.
Other evidence includes the 911 tape from the warning call made shortly before the explosion. There was no word on when Centennial Olympic Park would reopen, but authorities said it would be no earlier than Sunday. The IOC and the Atlanta Committee for the Olympic Games said that all Olympic flags would be flown at half staff during events Saturday, and that all venues would observe a moment of silence in the memory of the bomb's victims. In addition, the Turkish flag will fly at half staff in memory of cameraman Melih Uzunyol, who suffered a heart attack while covering the explosion and died en route to the hospital. Bomb went off 23 minutes after call Tom Davis of the Georgia Bureau of Investigation told reporters Saturday that the explosion occurred about 23 minutes after the warning call.