PRAGUE - The man who attacked two-time Wimbledon champion Petra Kvitova with a knife at her Czech home in December 2016 is facing up to 12 years in prison, a prosecutor's office said Friday. The 33-year-old culprit was charged with blackmail, among other things, on Friday. "If found guilty of the... crimes, he is facing five to twelve years in prison," it added. Kvitova suffered career-threatening injuries to her playing left hand as she fought off the intruder at her home in the eastern Czech town of Prostejov. Police said the attacker did not know whose flat he was entering after pretending to be a technician checking boilers. Despite grim forecasts by doctors, who even warned she might lose her fingers, the 2011 and 2014 Wimbledon champion returned in time for last year's French Open.