William Bradford Bishop Jr. was born on August 1, 1936, in Pasadena, California. His parents were Lobelia Amaryllis St. Germain and William Bradford Bishop Sr. He grew up in a family that encouraged education. Bishop attended South Pasadena High School. After high school, he pursued a higher education and graduated from Yale University in 1959. He earned a bachelor of science degree in history, although some reports suggest he might have studied American Studies instead. He later received a master's degree in international studies from Middlebury College. There are also claims that he earned a master's degree in Italian from Middlebury and a master's degree in African Studies from UCLA.

After graduating, Bishop married Annette Weis, who was his high school sweetheart. They had three sons together. Following his marriage, he joined the United States Army. He spent four years serving in counterintelligence. During this time, he learned to speak five languages fluently: English, Italian, French, Spanish, and Serbo-Croatian. After his military service, Bishop continued his career with the U.S. State Department. He held various positions in the Foreign Service and worked overseas in several countries.

Bishop's postings included time in Italy, specifically in the cities of Verona, Milan, and Florence from 1968 to 1972. He also served in Africa in locations such as Addis Ababa, Ethiopia, and Gaborone, Botswana, from 1972 to 1974. After returning to the U.S., his last posting was at the State Department headquarters in Washington, D.C., where he worked as an assistant chief in the Division of Special Activities and Commercial Treaties. At that time, he lived in Bethesda, Maryland, with his wife, their three sons, and his mother, Lobelia.

On March 1, 1976, William Bradford Bishop Jr. left his office at the State Department in Washington, D.C. after saying he felt unwell. His last confirmed sighting was outside his workplace. After leaving, Bishop withdrew several hundred dollars from a bank and purchased a ball-peen hammer, a gas can, a shovel, and a pitchfork. He filled the gas can with gasoline and returned to his home in Bethesda, Maryland, around evening.

Police believe that Bishop killed his wife first and then his mother when she returned home. Finally, his three sons, aged 5, 10, and 14, were killed while they slept in their upstairs bedroom. After the murders, Bishop drove the bodies about 275 miles to a wooded swamp in North Carolina. On March 2, he dug a shallow grave, piled the bodies inside, and set them on fire.

The bodies were discovered by forest rangers alerted by the smoke. They found a gas can, pitchfork, and shovel at the site, which led investigators to trace back to Bishop. He was reported to have purchased tennis shoes later that same day in Jacksonville, North Carolina, and was seen with his family dog and a woman described as "dark-skinned."

On March 10, a neighbor contacted police after noticing that the Bishop family had not been seen for several days. Investigators found blood at the Bishop residence, which led to dental records confirming that the burned bodies found in North Carolina were those of Bishop's family.

On March 18, Bishop's station wagon was found abandoned in Tennessee. The car contained several items, including dog biscuits, a bloody blanket, a shotgun, and a shaving kit with Bishop's medication. Witnesses believed the vehicle had been there for several days. Authorities suspected that Bishop may have mixed with hikers on the Appalachian Trail and attempted to track him down with bloodhounds but were unsuccessful.

A grand jury later indicted Bishop on five counts of first-degree murder. Despite extensive searches and investigations, Bishop eluded capture and has been listed as a fugitive since then. Numerous alleged sightings of him have occurred in various countries, but none have led to his arrest. Over the years, this case has been featured in multiple media outlets and shows seeking information on his whereabouts.