Hidden in Water
On Christmas Eve 2002, Laci Peterson, eight months pregnant, disappeared from her home in Modesto, Calif. Her purse, keys, and phone were left in her house. Laci's husband, Scott, reported her missing, saying he'd been out fishing that day. He gave several media interviews, apparently grieving, but then a woman surfaced who claimed to have been his mistress. She said he'd told her that he'd recently lost his wife, but that had in fact been two weeks before Laci disappeared. Sympathy turned to skepticism and suspicion.
On April 13 and 14, 2003, the partial remains of a fetus and a woman surfaced off Point Isabella Regional Park on the San Francisco Bay in Richmond, Calif. Investigators made a careful recovery of the remains, but scavenging by marine life made it difficult to determine a cause of death. This area of the recovery was about two miles from the area at which Peterson had said he had been fishing, which was incriminating. DNA tests confirmed that the remains were those of Laci and the unborn child, whom Laci had planned to name Conner. Underwater divers scoured the area, where water current studies indicated that the bodies were likely dumped.
Peterson disappeared, but April 18, near the border of Mexico, he was arrested with recently dyed hair and in possession of $15,000 in cash and his brother's ID. He was soon charged with two counts of murder. While examinations of the remains, which had been underwater for nearly four months, could not determine a clear cause or time of death, Peterson was nevertheless convicted of double homicide and sentenced to death.
Forensic handling of submerged bodies calls for special teams who not only have specific diving skills but knowledge of how to carefully collect evidence under water, handle a water-logged body, and preserve a crime scene. While many people think that water washes away all evidence, and oftentimes evidence does in fact deteriorate, water can sometimes have a preservative effect. In recent years, researchers have improved methods of collecting fingerprints from submerged items. There still remains little that can be done about damage to long-submerged corpses, but trauma can be examined on bones and differentiated from chewing or bite marks.
In fact, underwater forensics covers more cases than just murder victims, weapons and other evidence thrown into rivers, ponds, lakes, or oceans. Many drownings in bathtubs also require knowledge of water, physiology and physics to resolve. Too many have been viewed as accidents which careful investigators feel may have been overlooked homicidal drownings. Among the early cases of underwater forensics, before it was yet a distinct discipline, were the notorious "brides in the bath" murders. It took a shrewd mind to figure it out, and that only after a victim's relative insisted on an investigation.