Dion was, for many years, the head of the Justice Department's counter-espionage section.[ This position has to be approved by the Office of Personnel Management. Dion retired on October 31, 2013, replaced by Katie Kedian.]
According to Elaine Shannon and Ann Blackman, in The Spy Next Door, Dion was the first Justice Department official contacted after FBI agent Robert Philip Hanssen was discovered to have been an enemy spy.[6] According to Rowan Scarborough, in Sabotage: America's Enemies within the CIA, Dion was the first Justice Department official contacted after it was learned that senior White House aides had revealed to the press that Valerie Plame was a covert CIA case officer.[1]
References
1. ^1 2 {{cite book| url = https://books.google.ca/books?id=AiD54F3tpG4C&pg=PA133&dq=CIA+++%22John+Dion%22&hl=en&sa=X&ved=0ahUKEwiO0YPCwZ3NAhUXIlIKHW9zDvwQ6AEIGzAA#v=onepage&q=CIA%20%20%20%22John%20Dion%22&f=false| title = Sabotage: America's Enemies within the CIA| author = Rowan Scarborough| publisher = Regnery Publishing| year = 2007| isbn = 9781596986275| accessdate = 2016-06-10}}
2. ^1 {{cite book| url = https://books.google.ca/books?id=qdRXl0YAKtUC&pg=PT95&dq=CIA+++%22John+Dion%22&hl=en&sa=X&ved=0ahUKEwiO0YPCwZ3NAhUXIlIKHW9zDvwQ6AEIITAB#v=onepage&q=CIA%20%20%20%22John%20Dion%22&f=false| title = Tangled Webs: How False Statements Are Undermining America: From Martha Stewart to Bernie Madoff| author = James B. Stewart| publisher = Penguin Books| year = 2011| isbn = 9781101476512| accessdate = 2016-06-10}}
3. ^1 {{cite book| url = https://books.google.ca/books?id=O4ilvWokuKoC&pg=PT148&dq=CIA+++%22John+Dion%22&hl=en&sa=X&ved=0ahUKEwiO0YPCwZ3NAhUXIlIKHW9zDvwQ6AEIJzAC#v=onepage&q=CIA%20%20%20%22John%20Dion%22&f=false| title = The Spy Next Door: The Extraordinary Secret Life of Robert Philip Hanssen, the Most Damaging FBI Agent in U.S. History| author = Elaine Shannon, Ann Blackman| publisher = Little, Brown publishing| year = 2008| accessdate = 2016-06-10| isbn = 9780316055598}}
4. ^1 {{cite news |url = https://www.washingtonpost.com/wp-dyn/content/article/2009/08/20/AR2009082004295.html |title = Detainees Shown CIA Officers' Photos |publisher = Washington Post |date = 2009-08-21 |author = Peter Finn |archiveurl = https://www.webcitation.org/query?url=http%3A%2F%2Fwww.washingtonpost.com%2Fwp-dyn%2Fcontent%2Farticle%2F2009%2F08%2F20%2FAR2009082004295.html&date=2009-08-21 |archivedate = 2009-08-21 |quote = |deadurl = yes |df = }}