The law enforcement official, who led the FBI from 2001 to 2013, died Friday at age 81. Mueller joined the United States Marine Corps in 1968, and started his legal career in 1976, as an assistant prosecutor in the U.S. Attorney’s Office for the Northern District of California. He would spend the following decades as a federal prosecutor, moving to the U.S. Attorney’s Office in Massachusetts in 1982. In 1990 he was appointed assistant attorney general for the criminal division of the U.S, Department of Justice, where Mueller oversaw such high-profile cases as the bombing of Pan Am Flight 103. He was then appointed U.S. attorney for the Northern District of California in 1998. When that came to an end, Mueller was nominated as director of the FBI in 2001, just a week before the September 11 terrorist attacks. He stayed in that position until 2013, one of the longest tenures in history, second only to J. Edgar Hoover. In 2017 Mueller was appointed special counsel to oversee the Justice Department’s investigation into whether Russia had influenced the U.S. presidential election of 2016 to help Donald Trump.

The American virologist, who was cowinner (with Harold Varmus) of the Nobel Prize for Physiology or Medicine in 1989, died Friday at age 90. Bishop graduated from Gettysburg College in 1957 and from Harvard Medical School in 1962. In 1970 Bishop teamed up with Varmus to test the theory that healthy body cells contain dormant viral oncogenes that, when triggered, cause cancer. Working with the Rous sarcoma virus, known to cause cancer in chickens, they found that a gene similar to the cancer-causing gene within the virus was also present in healthy cells. In 1976 they published their findings, which proved invaluable to cancer researchers.