One of the FBI's 10 most-wanted fugitives, accused of the 38-year-old hammer slayings of his family of five, has ties to Southern California.
William Bradford Bishop, Jr., who was born in Pasadena, allegedly bludgeoned to death his mother, wife and three sons -- ages 5, 10 and 14 -- at their home in Bethesda, Md., on March 1, 1976.
Agents called him a "family annihilator" and blitzed the Internet last week with a social media and news publicity campaign to try to capture him.
The FBI is offering a reward of up to $100,000 for information leading to his arrest.
"If he’s dead, so be it," said Steve Vogt, the special agent in charge of the FBI’s Baltimore Division. "But until we know for certain, we will not stop searching for him."
Agents hope people who are active on social media will pay attention and help close the case. A forensic artist has produced a 3-D, age-progressed representation of Bishop to help the public identify him.
"When Bishop took off in 1976, there was no social media, no 24-hour news cycle," Vogt said. "There was no sustained way to get his face out there like there is today."
At the time of the killings, Bishop would have been in his early 40s. Today, he would be 77.
He has a 6-inch vertical surgical scar on his lower back and was fond of sporting his class ring from Yale.
Bishop is considered armed and dangerous. Investigators believe he is in the possession of a Smith and Wesson .38 revolver.
The Yale graduate speaks five languages, including French, Italian, Serbo-Croation and Spanish.
He is also capable of flying planes, and is an avid outdoorsman and hiker with an affinity for the Sierra Nevada Mountains, FBI officials said.
Bishop Jr. allegedly bludgeoned his family to death in their home in the Maryland suburbs of Washington.
It was the same day the former U.S. Department of State employee learned he had been passed over for a job promotion, authorities said.
After the slayings, he allegedly drove to a wooded area in North Carolina, dumped their bodies in a shallow grave and burned them, the FBI said.
The victims' bodies weren't identified until one week later, giving Bishop sufficient time to flee.
There have been sightings of him in North Carolina and Europe.
Anyone with information is urged to contact the FBI at 1-800-CALL-FBI or go online.
The Associated Press contributed to this report.