"The BOP is this key piece of physical evidence – perhaps the last best hope for putting the pieces of the puzzle of the Deepwater Horizon together," says John Rogers Smith, associate professor of petroleum engineering at Louisiana State University.
Thad Allen, the Gulf national incident commander, on Thursday gave the go-ahead for BP and Transocean, the drill rig operator, to replace the Deepwater Horizon's BOP with another and to bring the failed unit to the surface. But he warned BP that the BOP must be treated carefully to preserve evidence.
"Each procedure should recognize and preserve the forensic and evidentiary value of the BOP and any material removed from the BOP," he wrote in Thursday's directive to BP Chief Managing Director Bob Dudley. Along those lines, Justice Department investigators are now hunting for blowout preventer specialists who could conduct a forensic examination of the unit, one source told the Monitor.
The BOP may be the last best chance to find a "smoking gun" that tells investigators whether the blowout was a result of human error, mechanical failure, bad maintenance, faulty procedures – or a combination of those, industry experts say.