Sunday, the six full bodies and three heads underwent CT scans at the Edmonds Center for Diagnostic Imaging.

Home video from May 5 reveals the sound of the sonar testing from the Navy destroyer USS Shoup near the San Juan Islands. Whale experts say the video shows the orcas are clearly distressed.

Experts are now conducting tests over the next few weeks to see if the sonar fatally injured 13 harbor porpoises found dead.

Joel Reynolds, the Director of the Natural Resources Defense Council, says, "We know that this sort of sonar interferes with critical life functions. We know that it can injure them or even kill them. It's like dying from a very, very intense migraine headache."

In 2001, preliminary tests show a half dozen beached whales in the Bahamas were killed by sonar. CT scans showed bleeding around their ears and brains.

Sunday, CT technician Alan Grose found himself scanning frozen porpoises instead of people -- a difficult job. "Some of the frozen porpoises we've seen are not exactly symmetrical, they're curved this way and that."

Experts will look at the scans for anything unusual, such as inner ear damage or bleeding, but that's just part of it.

"We're looking for disease, we're looking at contaminate loads in these animals. We're also looking for any visible signs on the animal of any kind of thing that may have caused its death," says Lynne Barr with NOAA.

After the CT scans, the porpoises will be taken to the NOAA lab in northeast Seattle where the researchers will perform necropsies, looking at the organs and tissue for any further clues to what killed these mammals.

The NOAA scientists hope to have their preliminary report completed in a few weeks, but it could take longer if there is a great deal of conflicting data.