The Ergenekon trials are a series of high-profile trials which have taken place in Turkey in which 275 people, including military officers, journalists and opposition lawmakers, all alleged members of Ergenekon, a suspected secularist clandestine organization, were accused of plotting against the Turkish government. The trials resulted in lengthy prison sentences for the majority of the accused.
Since Istanbul Heavy Penal Court 13 accepted the 2,455-page indictment against 86 defendants in the first case against alleged members of the supposed clandestine organization Ergenekon on 28 July 2008 a further 14 indictments were submitted up to February 2011. Until the fourth indictment the number of defendants had increased to 531 and more than 8,000 pages of indictments had been written. Most trials are held in Silivri Prison. At the beginning the courtroom could accommodate about 280 people. In June 2009, the prison's sport hall was converted for the term of the trial into a maxi courtroom with a capacity for 753 people.
In April 2016, the country’s highest appeals court said the lower court’s convictions were being overturned because prosecutors had been unable to prove that Ergenekon actually existed.
The first hearing at Istanbul Heavy Penal Court 13 was held on 20 October 2008. The main charges are: establishing, directing, and being a member of an armed terrorist organization; aiding and abetting a terrorist organization; attempting to overthrow the government through the use of force and coercion; acquiring, stocking, and using explosives; and urging others to commit crimes using explosives.
The reading of the 2,455-page indictment lasted until 13 November 2008. In the 26th hearing on 15 December 2008 defendant one, retired General Veli Küçük spoke for the first time and pleaded not guilty. In January and February 2009 four defendants were released including retired General Hurşit Tolon. One defendant, lawyer Kemal Kerinçsiz testified from hearing 66 to hearing 78 on 20 April 2009.
On 30 January 2010 the defendants Dr. Emin Gürses, Dr. Ümit Sayın and Muhammet Yüce were released pending trial. The hearing was adjourned to 22 February 2010. During the hearing of 7 December 2009 Dr. Ümit Sayın had said that he was "secret witness" by the code name of "Anadolu". Subsequently his lawyer declined to defend him any further. During the hearing of 2 December 2010 (hearing 165) the defendant Alparslan Arslan, charged for the 2006 Turkish Council of State shooting, demanded to benefit from the law of repentance. Despite repeated demands of the presiding judge he did not reveal any details.