William Bradford Bishop Jr. hasn't been spotted for decades, but the FBI has used some computer magic to show what he might look like now. The cold case dates back nearly 40 years.
The FBI says Bishop bludgeoned his entire family to death then vanished. Now the search for bishop is renewed. The FBI says he may be hiding out in the open, close to his home town of Pasadena.
The FBI created a bust projecting what Bishop may look like today at 77.
"He is alleged to have killed his three sons, his mother and his wife," said FBI Spokeswoman Laura Eimiller.
Eimiller says Bishop worked for the State Department at the time of the killings in 1976.
Investigators say he killed them at their home in Bethesda, Maryland, dumped their bodies in a shallow grave in North Carolina, and burned them.
Bishop was last seen buying shoes in that area.
"This might be your neighbor, someone that's living among us, and all we need is that tip," said Eimiller.
Bishop was born in Pasadena and was known to be a big fan of the Sierra Nevada. Because of that, investigators believe he may be living in this area.
Last year, the FBI put together a task force to review this cold case. They hope the new attention may spur new tips from the public.
"He's very skilled, he's known to speak many languages, worked for the Foreign Service, is considered very intelligent, and so it's possible that he could be anywhere, but we don't want to rule out the possibility that he did come back home and is possibly living in plain sight," said Eimiller.
The FBI says they have no evidence Bishop is in Southern California. In fact, they say it's possible he's in Europe, living under a false name.
Bishop has a master's degree in Italian and is fluent in five languages.
The FBI is offering a $100,000 reward.