It happened on the night of March 1, 1976, in the gray-shingled split-level on Lilly Stone Drive in Carderock Springs, an upper-class Bethesda neighborhood, where police say William Bradford Bishop Jr., a cultured, high-ranking State Department official, beat his wife, Annette, 37, to death with a sledgehammer.
Authorities allege he then waited for his mother, Lobelia Bishop, 68, who lived with the family, to return from walking the dog, and then killed her with the same weapon.
Police say Bishop then moving onto the bedrooms of his three sleeping sons, William Bradford III, 14, Brenton Germaine, 10, and Geoffrey Cordon, 5, and in one final burst of fury, wielded the sledgehammer three more times, until they lay still in their blood-soaked beds.
The ensuing 30 years have brought few answers, but one thing remains certain: Bishop, indicted on five counts of murder by a Montgomery County grand jury, vanished and remains an international fugitive.
And despite highly advanced surveillance techniques, worldwide watch lists and interlocking computer networks, Bishop continues to elude the authorities while remaining at the center of one of Maryland's most gruesome and mysterious killings.
The passage of three decades has done little to diminish Bishop sightings and leads that still reach police. According to police and newspaper reports, he has been spotted in Spain, Italy, Sweden, Africa, Greece, England, Finland, Belgium, Russia and Switzerland.
"Sightings of Brad Bishop -- or someone people think is him -- are common around the world. People who see wanted posters and America's Most Wanted seem to believe they've spotted him in car washes, libraries, and even posing as a janitor at a Southern California school," reported The Sun in a 1997 article.
Bishop, who was fluent in five languages -- English, Spanish, French, Italian and Serbo-Croatian -- served in the Army for four years, where he was trained as a spy and worked in counterintelligence.
His Army days over, Bishop joined the State Department and had held assignments in embassies in Italy, Ethiopia, and Botswana. He returned to Washington, where he continued to rise in the department.
On March 12, 1976, he told his secretary that he was going home early because he was coming down with the flu. He was angry at being passed over for a promotion.
Earlier in the day, police say Bishop had withdrawn $400 from his account, and on the way home, they allege he made a stop at a Sears store in Montgomery Mall and purchased a sledgehammer and a 2 1/2 -gallon gasoline can. These were the two essential components authorities say he needed to carry out his horrendous plot.
After the killings, police say, Bishop loaded the corpses, covered in blankets, into the back of his 1974 maroon Chevrolet station wagon along with the Leo, the family's golden retriever. That began a horrid journey and Bishop's flight into anonymity.
Police believe he drove 275 miles through the night, heading for the Outer Banks, finally stopping in the swampy woods of Columbia, N.C., some 40 miles from the coast. There, police say, he dug a shallow grave and after placing the bodies in the pit, doused them with gasoline and set them ablaze.
Sixteen days after the bodies were found in the forest in March 1976, Bishop's blood-spattered car was found 400 miles away, abandoned in the Great Smoky Mountains National Park in Tennessee.
Inside were bloodied blankets, an ax and a shotgun. "Police bloodhounds picked up a faint scent of Bishop near the park's tourist center," observed The Sun in 1997.
For all practical purposes, this is the last known place where Bishop momentarily stood before departing for his new life, accompanied by his dog.
"The FBI has circulated Mr. Bishop's photograph and description throughout the world. It has placed `stops' with immigration authorities, credit agencies, Mr. Bishop's banks, airports, car rental agencies and any other type of business or service he could be expected to approach, including physicians, pharmacists and psychiatrists," reported The Sun a year after the killings.
How could Bishop have slipped away so easily? Some speculate he was able to flee the U.S. on false passports he earlier had issued to himself. Others suggest that he was a State Department or CIA spy. Both agencies have said this is not the case.
Montgomery County Sheriff Raymond M. Kight has never forgotten the case.
"I was a young deputy then, and I remember when we staked out Bishop's house, thinking that he might just be crazy enough to return. He never did," Kight said yesterday.
Kight says the case is open, and he assumes that Bishop is still alive.
"Lord knows he's getting older, but I have to think that he's still alive, and we're still continuing to look for him. We check out all credible leads," Kight said.
"And we are still getting hot and cold sightings -- even from as far away as Alaska. We have to check them out until we can prove otherwise,"
Recently, Kight's attention was drawn to a lonely North Carolina beach where a body had been brought in by the tide and washed up on the beach.
"The body had no hands and its jaw was slashed. It looked like a gang execution. Anyway, the man proved to be of Hispanic origin, and obviously not Brad Bishop. But still we checked it out," Kight said.
Working with the National Center for Missing and Exploited Children, Kight and his department hope an age-enhancement project showing how Bishop would look at 69, might help bring him to justice.
"We do age-enhancement posters and then distribute them. It's another tool," he said. "However, it's still an open case."