(CNN) -- The disappearance last autumn of three young Michigan brothers has turned into a murder investigation, authorities said Tuesday.
Residents in the small city of Morenci, Michigan, have searched two months for Tanner Skelton, 5, Alexander William Skelton, 7, and Andrew Skelton, 9, who were last seen at their father's home on Thanksgiving.
The father, John Skelton, who is charged with parental kidnapping, is the primary suspect, Police Chief Larry Weeks said at a news conference.
Weeks said that while he could not disclose much information, he wanted to put an end to "false hope" the boys would be found alive. He asked farmers and others to be on the lookout for their remains.
"When the time is appropriate, charges will be requested," Weeks said.
John Skelton told investigators he gave the boys to a group called United Foster Outreach and Underground Sanctuaries, Weeks said. No such group was found to exist, the chief said.
"It's just one example of misinformation that we have received from him that indicates the direction this investigation is continuing in," the chief said.
Skelton was arrested in December upon his release from a mental health facility where he was treated after a suicide attempt.
Skelton also said he left the three boys with a woman, whom he identified as Joann Taylor, the morning before he tried to take his own life -- in part to ensure that they did not witness his suicide attempt, police said.
Skelton said Taylor was supposed to return the boys to their mother at their home in Morenci, a southern Michigan town of about 2,400 people about 40 miles west-northwest of Toledo, Ohio, on November 26, Weeks said. But the boys never arrived.
Earlier, authorities determined that Skelton had no "established relationship" with the person he named as Taylor, and they aren't certain she even exists.
Kathye Herrera told reporters Tuesday the boys' mother, Tanya, and the family are experiencing "utter despair to a peaceful feeling knowing that the boys are in a better place."
"Andrew, Alexander and Tanner will be on their hearts and minds forever," said Herrera, thanking the community for aiding the family and helping in searches in Michigan and Ohio. "They will be missed not only by the family, but by friends, classmates and the entire community."
According to CNN Detroit affiliate WDIV, John Skelton appeared Friday for a brief court hearing as part of his divorce case. The judge asked him whether he was prepared to give the children to their mother, and he answered, "I can't," WDIV said.
Skelton family friend Bill Foster told HLN's Jane Velez-Mitchell he understood why Weeks made Tuesday's announcement.
"Too many people started believing they [the boys] could be with someone or an organization," he said.
The last time someone other than a family member saw the boys was at 5 p.m. on November 25, according to Weeks.
Police say Tanner is 3 feet, 6 inches tall, has strawberry-blond hair and blue eyes and weighs about 40 pounds. Alexander is 3 feet, 9 inches tall, has brown hair and eyes, weighs about 45 pounds and has scars on his hairline and chin. The oldest brother, Andrew, is 4 feet, 1 inch tall, has brown hair and eyes and weighs roughly 57 pounds.