Investigators continue searching for clues near the area of the deadly explosions during the Boston Marathon.
There are hundreds of investigators looking for evidence in the area.
Dr. Jacqueline Fish, a vice president at Charleston Southern University, trained 60 of those very investigators with the Boston Police Department.
"Boston is the best trained agency in the country because we've been there 3 times," she said.
Fish explains that there is currently a 24-hour, methodical, step-by-step search for information.
"The crime scene investigators are now dressed in their white coveralls and they are walking shoulder to shoulder looking for any fragment of evidence," she said.
Because this was an explosion incident, evidence can be almost anywhere.
"So, those shards of glass or remnants of metal can be seen anywhere. It's hard to tell just how far reaching that crime scene really is," she explained.
The grim reality is that there is still evidence with many of the victims who are spread out across hospitals in the Boston area.
"Each one of those victims can be considered a crime scene because of the shrapnel that is embedded in their bodies. Those are pieces of physical evidence as well," Fish said.
In that shrapnel could be the clue that cracks the case. Crime scene investigators have to be assigned to those hospitals as well.
"It's not like a doctor can go in and start removing those shards and toss them somewhere. A police officer has to be there to take custody," Fish said.
Other forensic teams are analyzing hundreds of pictures from the race and hours of video.