Officials in East Lansing are investigating what could be a death pact.   The bodies of Alfred and Jean Clausen, both 90 years of age, were found in their home in the 12-hundred block of West Saginaw Highway.  A note, detailing health problems the pair was having, was also found at the scene as an explanation of the crime.  Officials believe Alfred shot his wife of more than 60 years, then turned the weapon on himself.  Friends say the death could be a mercy killing.  Police are asking anyone who may have clues into what was going on in the home to contact them.