Who killed Michael and Kathleen Greene?

PIERSON TOWNSHIP, Mich. (WOOD) - Michael and Kathleen Greene's home on Big Whitefish Lake has been torn down. The evidence from their murders a year ago was collected long ago.

But the police don't yet have a suspect.

On October 28, 2010, the Greenes were found dead in their burned home on the north side of Big Whitefish Lake in Pierson Township. They were stabbed to death and then the house was set on fire.

"Any time it takes...a year on a major case like this and you haven't got it solved, frustration can be there," Montcalm County Sheriff Bill Barnwell told 24 Hour News 8.

Barnwell told 24 Hour News 8 his detectives consulted with a criminal profiler from the Federal Bureau of Tobacco, Firearms and Explosives .

The profiler believes this was a personal crime, since the Greenes' throats were slashed.

Michael Greene was 59 when he died. He was an executive with IBM who traveled extensively and was known to keep a lot of money in the house. But not much money was found after their bodies were discovered.

Authorities have cast a wider net looking for suspects, perhaps someone he met in his travels.

"He could have ran upon somebody in his travels and led them back to his home," Barnwell said. "Or something occurred between him and someone else. Or even Kathleen, as far as that's concerned."

That's one reason investigators are considering asking the TV show America's Most Wanted to take up the case.

"Perhaps someone will pick this up in one of the other markets... maybe out of state.... could be anywhere. And they could recognize the face, Recognize the information."

The Greenes may have known their assailant or assailants, since there's no evidence the home was broken into.

"Either the doors were unlocked or they let them in," Barnwell said.

The biggest lead in the case remains the large white SUV seen near the home the night of the murders, and the sketch of a man possibly seen in the area that night.

"We're hoping that maybe someone, maybe the killer or killers, have talked to somebody either inadvertently or may have said something," Barnwell said. "We're hoping that someone can come forward and give us information that puts us towards the right people."

On the Net:

Information on the Greene case (pdf)