BETHESDA, Md. (WUSA) -- What could drive someone to kill 3 children as they slept by hitting them over the head with a metal mallet? Plus kill the childrens' mother and grandmother?
This has been the question baffling a Montgomery County, Maryland, community and law enforcement for decades. Thirty five years later, the killer is still on the loose.
By all outward appearances, all was well with the Bishop family.
"They look like the all-American family," says Montgomery County Sheriff Darren Popkin, who has worked this case for 20 years. "They appeared to be very happy."
However, according to Popkin and Montgomery County Police, on March 1, 1976, William Bradford Bishop, a U.S. State Department official, left work early saying he didn't feel well. Then, according to law enforcement, Bishop went to Montgomery Mall and bought a gas can and small metal mallet at Sears. Then, he drove to the other side of the mall, filled up the family station wagon with gas as well as the gas can he had just purchased. He then went to the bank and withdrew almost all the money: $400.
MORE: Wanted Information on William Bradford Bishop
Afterwards he made the 15-minute drive to the neighborhood of Carderock Springs in Bethesda, walked into his house and killed his entire family using the mallet.
"He went from room to room," says Popkin. "And one at a time hit them around the head and and killed each one of them."
Popkin says Bishop killed his wife first. Then, he killed his 3 young sons as they slept in their beds. Shortly after this, Popkin says Bishop's mother entered the house after walking the family dog. She was the last to be killed.
"It was just a horrific scene," says Popkin.
What happens next is perhaps just as horrific. Authorities say Bishop puts his dead family in the back of the family's maroon station wagon and headed south for a 6-hour drive to North Carolina.
"A park ranger saw fire burning and immediately went to see what was going on. What he found was just absolutely grizzly. The discovery of 5 bodies in a shallow grave that was burning," says Popkin.
It took a week before police could identify the bodies: 68-year-old Lobelia Bishop, 37-year-old Annette, 14-year-old William, 10-year-old Brent and 5-year-old Geoffrey.
In the time it took to identify the dead family members, William Bradford Bishop had disappeared.
Bishop's station wagon was found abandoned in the Tennessee mountains. Blood was found in the car. Bishop's diplomatic passport has never been found.
"I do believe Mr. Bishop is still alive," says Sheriff Popkin. "We do believe he's out there somewhere."
Bishop's career with the State Department, and before that the CIA, took him all over the world. He is fluent in 5 languages. While he worked at the State Department, says Popkin, one of Bishop's duties was making passports.
"He had the access to create whatever he wanted," says Popkin. Plus Popkin adds, "There was no verifying names on plane tickets back then in 1976 like there is now."
Over the past 35 years there have been Bishop sightings in Stockholm, Sweden, Sorrento, Italy, and Basel, Switzerland. Two years ago there was a report he was dead in Hong Kong. As recently as a year ago, a report he was dead in France outside of Paris.
"It was not Mr. Bishop in either case," says Popkin. "Fingerprints verified that.
"There is nothing more that I would like to do is be able to put those handcuffs on Mr. Bishop and bring him back here."
If he is alive, William Bradford Bishop will be turning 75 in August.
As for a motive in the killings, co-workers at the time say Bishop was passed over for a promotion right before his family showed up dead. Neighbors at the time talked about financial problems and Bishop's desire for overseas work and his wife Annette's desire to stay in Maryland.
What is known for sure is Bishop was seeing a psychiatrist and taking medication for anxiety and depression, says Popkin.
But the real motive, says Popkin, won't be known until they catch their man.
The Montgomery County Sheriff's Department encourages anyone with information on this case to contact them at 240-777-7000.