Friday will mark the one-year anniversary of the homicides of Robert and Colleen Grube in their Fort Recovery farmhouse.

Mercer County Sheriff Jeff Grey spoke to media Thursday morning, where he said interviews have been conducted with over 250 people and over 200 pieces of evidence has been submitted to the lab for analysis over the past year.

“My confidence level remains high that we will be successful,” he said.

The father and daughter were found Nov. 30 bound with duct tape and shot, following what appeared to be a robbery of the farmhouse in Fort Recovery where they lived. Colleen, 47, lived there and took care of Robert, 70, who was disabled.

Grey said today several people have been ruled out as suspects, and any and all tips received are followed up on. The Grube homicides and the homicide of Melinda Shinn in Rockford remain the highest priorities, he said.

He declined to answer any questions from the media.

“Due to the progress of the ongoing investigations, we have to be very careful in what is released today. Hopefully soon, more information can be released,” he said.

A $20,000 reward is being offered for any information that leads to the arrest and conviction of those responsible.