Police in Clinton County, Missouri, are continuing their search for two missing Wisconsin brothers, Nick Diemel, 35, and Justin Diemel, 24, who disappeared over a week ago after traveling for business.

According to a local news outlet, the investigation has zeroed in on the property of Garland Nelson in Braymer, Missouri. GPS records and security footage seem to indicate the farm as the Diemel brothers’ last location. Seen on camera leaving their hotel on the morning of July 21, GPS indicates the brothers’ truck arrived at Nelson’s property around 9:30 a.m. At 11:44 a.m., the truck leaves the property and at 12:03 p.m. a general store camera catches the vehicle moving south on the 13 highway with no passenger in the front.

The truck was left in a commuter lot in Holt, Missouri, where it was found with keys in the ignition and lights on after the men were reported missing. Nelson was charged with “knowingly and without the consent of the owner unlawfully operated an automobile” and has since reportedly admitted to taking the truck and leaving it in the lot.

Despite this, no charges have yet been filed in relation to the disappearances of the Diemel brothers. Larry Fish, Sheriff of Clinton County, has stated the investigation has transitioned from missing persons to a death investigation but has not elaborated on why.

“We have a lot of leads that have come in,” Fish said. “A lot of people have provided a lot of support. And we are diligently working on those leads. It’s going to be long-term. It’s going to take some time.”

The St. Joseph News-Press on Wednesday reported that a Wisconsin probate court lists the date of death for the Diemel brothers as July 21 but that the filing does not identify the cause of death and neither filing has been approved by the court.

Missing Toddler In this representational photo, police tape seals off a street where authorities are searching a home after three people were arrested in connection with the disappearance of missing chef Claudia Lawrence in York, England, April 22, 2015. Photo: Getty Images/ Christopher Furlong