A Connecticut man with a history of mental illness reportedly confessed to killing his mother, who was reported missing by her sister days earlier.

WFSB reported that the missing persons investigation involving Donna Tucker, 60, turned into a murder investigation Friday afternoon. The woman’s son, Kyle Tucker, 34, gave police a “very detailed confession” that took more than an hour Sunday, according to the station.

The 60-year-old’s remains were reportedly discovered in the yard of her Hamden home; police said she died from blunt force trauma to the head. Reports indicated that a weapon hasn’t been recovered.

Donna was reported missing by her sister Friday as it wasn’t normal for the pair to not speak for a day. The New Haven Register reported that Kyle claimed his mother had been dead for “several hours” before she was reported missing.

The Hartford Courant reported that Kyle and Donna lived together. Hamden police chief Thomas Wydra said Kyle had a history of mental illness and officers had been called to the home for disturbances related to his mental state.

Despite this, Wydra said police “didn’t have cause to believe he would bring harm to his mother.”

While a motive for the slaying is not immediately known, WTNH reported that interviews with relatives led police to zero in on Kyle early on in their investigation. Neighbors also claimed they saw a bonfire being burned on the property around the time of Donna’s disappearance.

The station also claimed to have located Kyle’s Twitter account, which was reportedly packed with suspicious tweets about his mother—some which were posted on the day she was reported missing and the day her body was found.

Kyle, who has no arrest record, faces murder and destruction of evidence charges. He remains behind bars on a $5 million bond.

[Featured image: Donna Tucker, Kyle Tucker/Hamden Police Department]