The 25-year-old was sentenced to three years and nine months in prison for his role in a string of robberies in December 2011, but has long since put his past indiscretions behind him - opening his top-flight account against Bayer 04 Leverkusen on Matchday 7 of the 2014/15 campaign - in a near-miraclous tale of sporting absolution.
Two sides of the coin
A standout performer at amateur level for the likes of Berliner AK 07 and Türkiyemspor Berlin, Koc was already drumming up plenty of interest before regional outfit SV Babelsberg 03 came calling in 2010. He made 26 appearances in his debut season as a professional, but his efforts on the job masked some rather unsavoury events closer to home in the Moabit district of the German capital.
On 18 April 2011, police swooped on the apartment the undeniably gifted midfielder shared with his brother. Four others were also arrested and later put on trial as suspects in a spate of aggravated robberies at local casinos and cafes, before judgement was eventually passed towards the end of the year. A profusely repentant Koc - the reported getaway driver - was handed a 45-month jail term.
During the first 11 months of his sentence, Koc spent up to 23 hours of the day cooped up inside a seven-square-metre cell, only occasionally venturing outside to showcase his forgotten talents on the prison's no-frills pitch. "It was the worst time of my life," Koc recalled in a candid interview with German monthly sports magazine 11 Freunde. "I only feel good when I'm playing sport."
Opportunities to pursue his one true passion at a premium, the Berlin native wrote a number of heartfelt letters to some of his former Babelsberg colleagues asking for forgiveness. The response was overwhelming and gave him reason to believe his career as a footballer still had legs to burn. "It gave me hope," Koc explained. "So I started to work out in my cell. I kept the faith."
'I want to be a role model'
Granted early release on the grounds of good behaviour in spring 2013, it wasn't long before Koc was rewarded for his commendable approach to the emotionally draining rehabilitation process. "If he regrets what he's done, he deserves another shot," affirmed Babelsberg president Thomas Bastian after offering the reformed midfielder an unforeseen one-year deal back at the club. "That's what we're about."
Koc netted eight goals in 14 appearances during his second stint at the Potsdam-based outfit, garnering subsequent interest from, among others, Paderborn, where his fairytale story of redemption has continued to write itself since joining the club in January 2014. "Football gave me a new lease on life," he intoned after last May's historic promotion from the second tier. "I want to show people that football goes way beyond the pitch. I want to be a role model for disengaged kids. My parents can be proud again."