Federal prosecutors say alleged Turkish murder-for-hire mastermind Serhat D. Gumrukcu has a documented history of fraud and fleeing criminal charges. Gumrukcu, 39, has been accused along with three other men in connection with the kidnapping and murder of Danville resident Greg Davis, 49, in 2018. Gumrukcu remains in federal custody in Los Angeles, Calif. while he awaits his detention hearing scheduled for Wednesday. Gumrukcu has told the court he is willing to post $6 million dollars in bail so he could be released pending trial on a federal racketeering and murder charge. But on Monday, United States Attorney Tracy L. Wilkison of California filed a 17-page motion asking the court to keep Gumruku behind bars.