Pieces of the bomb have been sent to a Georgia law enforcement lab for further analysis. CNN has learned that investigators have videotapes and snapshots and are studying pictures from surveillance cameras that ring the park. An eyewitness saw four white men dressed in black. They were reportedly acting rowdy and drawing attention to themselves before the explosion. In the days before the bombing, federal officials told CNN a group of skinheads with a reputation for violence was being monitored.
Officials say that is another bit of information being pursued.
Other evidence includes the 911 tape from the warning call made shortly before the explosion. FBI special agent Woody Johnson said the explosive consisted of at least one pipe bomb in a knapsack with nails and screws to provide shrapnel. Tom Davis, a Georgia Bureau of Investigation agent, told reporters Saturday that the explosion occurred about 23 minutes after the warning call. Davis said he told the guard that they would try to find the package's owner, and if they failed to do so, would treat the parcel as a suspicious package. She died at the scene, apparently of massive head injuries, her relatives said.