Tests ahead to see if remains are Shannan's

Investigators will perform a battery of tests on the remains found in a marsh near the Oak Beach community where Shannan Gilbert was last seen on May 1, 2010.

Max Houck, a forensic expert and vice president of Forensic and Intelligence Services in Arlington, Va., said they're trying to answer two questions: Whose remains were recovered, and how did the person die?

Suffolk investigators say the process could take weeks and includes X-rays and bone analysis, as well as extracting DNA, adding that gleaning material from skeletal remains takes longer than sampling from soft tissue.

DNA tests are very reliable for determining identity, Houck said, but the viability of the test depends on how degraded the remains are.

Exposure to the elements in a moist and sometimes warm environment -- like Gilgo Beach -- where animals and insects roam could force the remains to decompose rapidly, lessening the likelihood that they will yield a large enough sample of DNA for identification, Houck said.

Finding out how the person died consists of pinning down the manner of death -- suicide, accident, homicide or natural -- and the cause of death, such as asphyxiation or gunshot wound.

Houck said one question is harder to answer than the other.

"They may not be able to determine cause of death, but they may be able to determine manner of death," he said.