There have been about 21 half-lives that have gone by since the alleged Po-210 poisoning occurred. After 10 half-lives, scientists generally consider that the isotope no longer exists. Since Po-210 decays to Pb-206 (that is a form of lead), the investigation would be looking for elevated levels of lead in the remains. It will be interesting to see if this pans out. I recall a Russian FSB agent who defected to England and worked for MI5 or MI6 who was killed by Po-210 poisoning in 2006 - Alexander Litvinenko. If Arafat succumbed to the same poison 2 years earlier, then the finger may point to the Russians!
Neurologist and author Oliver Sacks dies at 82 (Haaretz)