LUDINGTON, Mich. (WWJ/AP) – A hearing is set for December on prosecutors’ appeal of the dismissal of a murder charge against a Michigan man accused of killing his missing infant daughter.

The hearing date of Dec. 5 was set Thursday. Arguments will be held in Mason County Circuit Court.

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State and county prosecutors are appealing District Judge Peter Wadel’s September ruling that threw out an open murder charge against 24-year-old Sean Phillips.

Phillips’ daughter Katherine, a 4-month-old widely known as “Baby Kate,” disappeared in June 2011 in the Ludington area, about 80 miles northwest of Grand Rapids.

Wadel in April called a time-out in the trial to allow defense experts to examine a letter authorities say links Sean Phillips to his daughter’s disappearance. Phillips’ handwritten letter to the girl’s mother allegedly says the baby was accidentally killed and left in a “peaceful place.”

A copy of the letter was obtained by WOOD-TV8. Click here to read the letter (.pdf format)

Months later, Wadel dismissed murder charges, saying there isn’t enough evidence she’s dead or that Phillips committed murder.

Phillips has been imprisoned since 2012, serving a 10 to 15 year sentence after being convicted of unlawful imprisonment for failing to return Katherine to her mother, Ariel Courtland.

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Courtland has said Phillips told her that Katherine is still alive, but extensive searches haven’t turned up the girl. Investigators have also tried to find the girl’s body by examining seeds and other plant material on Phillips’ shoes.

Prosecutors say Phillips took the baby from Courtland because he feared a court-ordered paternity test would show he was the father. Courtland said Phillips wanted to put Katherine up for adoption, but she refused.

According to court testimony, officers from the Mason County Sheriff’s Department went to Phillips’ house on June 29, 2011 to talk to him after hearing about Katherine’s disappearance. Phillips allegedly told officers that the baby was with her mother, repeating that response three times.

When police asked whether Phillips was telling the whole truth, officers said he answered, “You’re right. I’m not telling you the whole truth.” That’s when officers noticed something was in Phillips’ cargo shorts pocket and did a pat down, finding baby clothes wadded up in a ball, according to court documents.

When one of the officers asked Phillips what it was, he answered, “Her clothes.” Officers immediately put Phillips in handcuffs.

Baby Kate’s body has never been found.

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