A Michigan father nearing the end of his sentence for falsely imprisoning his three young sons will not be leaving jail anytime soon.

John Skelton, aged 53, now faces murder charges for the deaths of his sons — Andrew, 9, Alexander, 7, and Tanner, 5 — over a decade after they were last seen. Fifteen years ago, during a Thanksgiving visit, Skelton did not return the boys to their mother. He spun various tales about their whereabouts, including a story involving an “underground sanctuary” where he supposedly left them with strangers for safekeeping. After the boys were legally declared deceased, authorities accused Skelton of murdering them and concealing their remains.

Currently, Skelton is held in the Lenawee County Jail with a bond set at an astronomical $60 million.

The murder charges came to light on November 12, just weeks before Skelton was due to be released from prison after serving time for the unlawful confinement of his sons. He was convicted in 2011, approximately a year after their disappearance. Up until last week, no charges had been brought against him concerning their deaths.

According to local ABC station WTVG, police conducted a prison interview with Skelton earlier this month in a bid to extract information that might lead to discovering the boys. However, an affidavit accessed by WTVG notes that Skelton was “uncooperative” and failed to provide any fresh leads.

The affidavit further outlines that Skelton has “consistently misled” investigators since the boys vanished in 2010. Police have confirmed that the supposed “underground sanctuary,” where Skelton claimed to have left the children to protect them from danger, does not exist. While details of newly acquired evidence remain undisclosed in the affidavit, authorities stated that Skelton deliberately hid his sons’ bodies to obscure the truth about their deaths.

According to the affidavit, Skelton searched the internet for different ways to kill people during November 2010, the time period leading up to the Thanksgiving the boys disappeared. When Skelton’s ex-wife, Tanya Zuvers, went to get her sons after the holiday was over, she found out that they were gone. Skelton was also hospitalized after he injured himself during a failed attempt to take his own life. When he provided several different stories about where the boys were, Zuvers reported them missing.

Police said that Zuvers asked to end her marriage to Skelton two months prior and was seeking sole custody of the children.

Skelton was charged with three counts of open murder and tampering with evidence. His next court date is scheduled for Nov. 24.