Here's a look at what you need to know about cases where U.S. judges have been targets of violence. Three federal judges were targeted and murdered from 1979 to 2012: Judge John Wood, Judge Richard Daronco, and Judge Robert Vance.
In January 2010, the U.S. Justice Dept released a report detailing threats or inappropriate communications made to judges between 2003 and 2008. Over five years the number increased from 592 to 1,278.
U.S. Marshals Service The U.S. Marshals Service is in charge of protecting federal judges.
"The Marshals Service protects more than 2,000 sitting federal judges and countless other court officials at more than 400 court facilities throughout the nation." (U.S. Marshals Service)
Timeline: June 3, 1974 - Washington state Superior Court Judge James Lawless is killed by a mail bomb in his chambers. Ricky Anthony Young is convicted of the crime.
May 29, 1979 - U.S. District Judge John Wood is killed by a contract killer allegedly tied to a drug-smuggling case the judge is handling. Three members of the Chagra family are later convicted of conspiring to kill Judge Wood. One of the Chagras had been scheduled to appear before Judge Wood in the drug smuggling case.
1983 - Illinois Judge Henry Gentile is shot and killed in his courtroom by a man whose divorce case is being handled by Judge Gentile. The man had hidden the gun used in a blanket in his wheelchair.
March 20, 1987 - Joel Cacace of the Columbo crime family hires hitmen to kill federal prosecutor William Aronwald. By mistake they tail Aronwald's father, George, a 78-year-old city administrative law judge who shares an office with his son. They kill Aronwald when he stops to pick up his laundry.
Sept. 14, 1987 - Mississippi Circuit judge Vincent Sherry and his wife Margaret are killed in their home. The murders are tied to a prison scam run by former Biloxi mayor Pete Halat who shared a law office with Sherry. Prosecutors say Halat believed the Sherrys may have taken some of the scam profits for themselves.
May 21, 1988 - U.S. District Judge Richard Daronco is shot and killed at his home in Pelham, N.Y. by a man was upset over Daronco's dismissal of the man's daughter's sexual discrimination suit.
1989 - Federal Appeals Court Judge Robert Vance is killed in his home in Birmingham, Alabama when he opens a mail bomb. Walter Leroy Moody Jr. is convicted of the death of Vance and attorney Robert Robinson. Prosecutors allege Moody sent the mail bombs out of anger over his conviction in 1972 for possessing a mail bomb.
March 18, 1999 - Los Angeles County Court Commissioner H. George Taylor and his wife Lynda are shot and killed at their home in Rancho Cucamonga. Investigators believe the shootings are "court-related" but the case remains unsolved.
February 28, 2005 - The husband and mother of U.S. District Court Judge Joan Humphrey Lefkow are shot to death inside the Lefkow's Chicago home. A former plaintiff whose case had been dismissed by Judge Lefkow claims credit for the murder in a suicide note.