Tekin graduated from the Turkish Military Academy in 1972, where he had been a classmate of Cem Ersever, and served in the Special Warfare Department. He participated in the Turkish invasion of Cyprus,[2] and according to Oktay Yıldırım was "the only lieutenant who ever received a gold medal for his work in the Cyprus Peace Operation".[3] He was forced to retire in 1986, having reached the rank of captain,[2] due to a Supreme Military Council (YAŞ) decision in relation to a fight Tekin was involved in.[4] In 2007 he said that he had served in the armed forces together with Oktay Yıldırım,[5] and said that Yıldırım was "like my son".[6]
Tekin was a partner in finance company Doğuş Factoring, in which Turkish Council of State shooter Alparslan Arslan worked as a lawyer.[7] In 2007 Sabah published claims, which it said were based on German police reports, that Doğuş Factoring had been used to launder drug money, and that Tekin was the lead organiser of the drug operations.[8]
On 5th August 2013, Tekin was sentenced to consecutive life sentences.[10]
On 10th March 2014, upper courts determined, that the rulings made in the Ergenekon case, were improper and therefore released all prisoners. Since all these cases were proven to be a set up against the Turkish military forces with the intent to weaken them.[11]
