Detectives say they have little to go on because the killer leaves almost no trace of even being there, in most cases, not even a drop of blood from the butchered animals.
Officials say it's impossible to know exactly how much and what type of weapons have been dumped in the ocean because of incomplete records. A 2001 Army report found 74 past instances of ocean disposal — 32 off U.S. shores and 42 off foreign coasts.
For example, in 1967 the Army dumped 4,577 one-ton containers of a mustard agent and 7,380 sarin rockets off the New Jersey shore, according to Army records.
Only some of the ocean dumps were mapped, and chemical munitions have been found in areas they weren't supposed to have been dumped, such as off Hawaii, said Craig Williams of the Chemical Weapons Working Group, a Kentucky-based organization."
So that's reassuring.
Also last September, a senior figure close to Israeli intelligence told the BBC that Israel had been linked to the interception of the Arctic Sea.
The source said Israel had told Moscow it knew the ship was secretly carrying a Russian air defence system for Iran. There has been no official confirmation of the report.
