Jeffrey and his mother Althea were last seen on March 27, 1973. They resided in Port Townsend, Washington. Their roommate, Glenn Allan Bagley, says he dropped them off at the Seattle-Tacoma International Airport that day. Althea and Jeffrey planned to travel to Greece to meet her parents, who were vacationing there. They were supposed to catch a United Airlines flight to New York City and then on to Greece. They never arrived in Greece and have never been heard from again. There was no record that either Althea or Jeffrey boarded any flights that day.

Bagley is the prime suspect in the Blankinships' disappearance, as well as the 1976 disappearance of his ex-wife, Esther Gesler, who was driving his car the day she vanished. Photos of him are posted below this case summary. Although Bagley claimed Althea and Jeffrey went on vacation to Greece, her cousin found her passport in a relative's home in 2002 and it had no entries in it. Althea was never issued another passport, making it unlikely she and Jeffrey left the country. As Althea's child, he could have traveled on her passport. Her cousin also found a cache of letters from Bagley to Althea. They had apparently had a romantic relationship.

Bagley, a retired civil engineer, presently lives in Manila, the capital of the Philippines. Washington police haven't spoken to him since 1976; he moved to the Philippines shortly after Gesler disappeared. He maintains his innocence in all three disappearances. Investigators are trying to build a murder case against Bagley, although it's unclear whether he can be extradited even if charges are filed against him.

Althea and Jeffrey's cases remain unsolved and foul play is suspected.

Left: Glenn Allan Bagley, circa 1970s;
Right: Bagley, circa 2009