Question: What former Federal Bureau of Investigation agent is the film Breach based on?
Context: Blood Oath is a novel published in 2010 by Christopher Farnsworth.  It centers on three main characters: Nathaniel Cade, a vampire more than 160 years old, currently bound by a blood oath to serve and protect the President of the United States; former Federal Bureau of Investigation agent Agent William Griffin, or "Griff," Cade's handler for more than 30 years, and Zach Barrows, a former White House staffer that is Griff's replacement.  The novel focuses on a deadly new threat to the United States from a horrible biological attack. Aubrey Lewis (c. 1935 – December 10, 2001) was an American football player and track athlete who was the first African-American to be captain of a Notre Dame Fighting Irish athletic team and a member of the first Federal Bureau of Investigation agent training program to include black people. Frank Elliott Barnett (July 20, 1933 – July 15, 2016) was the 49th Governor of American Samoa from October 1, 1976 to May 27, 1977.  Before becoming governor, he was a Federal Bureau of Investigation agent and a Tennessee attorney.  He served as the first Lieutenant Governor of American Samoa for two years prior to his governorship.  While governor, a number of Samoans signed a petition accusing him of abusing local officials; others signed a counter-petition supporting him, and the charges were eventually dropped.  This arose from his firing of Mere Betham, a native who had been serving as Samoan Director of Education, an action he defended as necessary to improve education on the island, but others decried as racist; Barnett reinstated Betham one week after dismissing her. Bruce J. Gebhardt (born 1949/50) is an American former Federal Bureau of Investigation (FBI) special agent who served as Deputy Director of the Federal Bureau of Investigation. Robert Philip Hanssen (born April 18, 1944) is a former Federal Bureau of Investigation (FBI) agent who spied for Soviet and Russian intelligence services against the United States for 22 years from 1979 to 2001.  He is currently serving 15 consecutive life sentences at ADX Florence, a federal supermax prison near Florence, Colorado. Robert Alan "Bob" Levinson (born March 10, 1948) is an American former Drug Enforcement Administration and Federal Bureau of Investigation agent who disappeared mysteriously in 2007 in Kish Island, Iran.  He is believed to be currently held captive by the government of Iran.  He disappeared on March 9, 2007, when visiting Iran's Kish Island while supposedly researching a cigarette smuggling case.  U.S. officials believed Levinson had been arrested by Iranian intelligence officials to be interrogated and used as a bargaining chip in negotiations with Washington.  But as every lead fizzled and Iran repeatedly denied any involvement in his disappearance, many in the U.S. government believed Levinson was probably dead.  He was subsequently revealed to be alive.  On December 12, 2013, the Associated Press reported that their investigations revealed that Levinson had been working for the Central Intelligence Agency (CIA), contradicting the U.S.'s statement that he was not an employee of the government at the time of his capture. Breach is a 2007 American historical and political thriller film directed by Billy Ray.  The screenplay by Ray, Adam Mazer and William Rotko is based on the true story of Robert Hanssen, an FBI agent convicted of spying for the Soviet Union and later Russia for more than two decades, and Eric O'Neill, who worked as his assistant and helped bring about his downfall.  O'Neill served as a consultant on the film.  The film received generally positive reviews. Howard Drummond Smoot, known as Dan Smoot (October 5, 1913, in East Prairie, Mississippi County, Missouri – July 24, 2003, in Tyler, Smith County, Texas), was a Federal Bureau of Investigation agent and a conservative political activist.  From 1957 to 1971, he published "The Dan Smoot Report", which chronicled alleged communist infiltration in various sectors of American government and society. Joe Navarro (born 1953) is an American author, public speaker and former Federal Bureau of Investigation (FBI) agent and supervisor.  Navarro specializes in the area of nonverbal communication and body language and has authored numerous books, including "What Every Body is Saying", "Dangerous Personalities", and "Louder than Words". Raúl González Salinas (born November 8, 1947) is a private security consultant, a businessman, and a retired Federal Bureau of Investigation agent who is the former mayor of Laredo, Texas.
Answer: Robert Philip Hanssen