A Michigan father has been formally charged with the murder of his three sons, who disappeared without a trace in 2010. The charges were announced on Wednesday.

According to WTVG, John Skelton is now facing three counts of open murder and evidence tampering in Lenawee County. Skelton has been incarcerated since 2011 for kidnapping his sons—Andrew, 9, Alexander, 7, and Tanner, 5. He was due for release on November 29.

Earlier this year, the boys’ mother, Tanya Zuvers, successfully petitioned to have them legally declared dead. Despite this, a judge concluded there wasn’t enough evidence to prove they were murdered around November 26, 2010, nor that their deaths were at the hands of their father.

READ: What Happened to the Skelton Brothers?

At the time of the boys’ disappearance, Zuvers had sole custody amidst divorce proceedings with John Skelton. The children had spent the holiday with Skelton, and were supposed to return to their mother the following day. Throughout the investigation, John Skelton provided various accounts of their disappearance, including claims that he handed them over to an organization to shield them from alleged abuse by their mother—allegations that Zuvers firmly denies.

FBI Special Agent Corey Burras said John Skelton searched online about how to break a neck, potassium cyanide, and rat poison. The searches were allegedly conducted the same month his sons disappeared.

The FBI agent also alleged that John Skelton addressed Zuvers in a suicide note, stating, “You will hate me.” Burras said he believed the note implied that he killed their sons.

John Skelton appeared virtually at March’s hearing to declare his sons legally dead. He did not provide any information about their whereabouts.

“I’m at a disadvantage. Anything I say isn’t going to make a difference,” he said.

This story is developing…