Sometimes, even after a murder conviction, some see reasonable doubt that the conviction was a righteous one.
Such is the case in the murder of Dennis and Merna Koula in La Cross, Wisc, a quiet community.
Their son Eric was found guilty and is currently serving two consecutive life-sentences for the murder of the wealthy couple.
It was Eric Koula who found the body. It was Eric Koula whose alibi didn't stand up. Eric Koula was broke.
Yet as CBS News' "48 Hours" reported, there are some inconsistencies that some can't quite put aside. They include John Christophersen, a special agent at the time with the Wisconsin Department of Justice.
It was said at the trial that Eric Koula treated his father as an ATM. There was a $50,000 check that he cashed right after his parents died.
It was a check from his father. Eric Koula had forged the signature -- something he claimed to have done many times.
But, as his attorney said at the trial: "What sort of an idiot would put a check in the bank the morning after they killed their parents, knowing that bank records are easy to get?"
To some eyes, the murder seemed like a professional hit. No valuables were taken. And there was no DNA evidence to implicate Eric Koula.
Moreover, there was another idea that investigators began to pursue at the time. A neighbor of the Koula's, Steve Burgess, freely admitted that he had received death threats. He was the president of a local bank.
And, as the CBS News investigation indicated (embedded, but there are some gaps in the audio), if you use Google Earth to locate Burgess' house, you get a surprise.
"48 Hours" correspondent Peter Van Sant said: "In fact, when you Google Earth Steve Burgess' address...the zoom into the house goes to the Koula's house, not to Steve Burgess' house."
Police say they discounted the threatening caller, as they located him and he had an alibi. But then could that individual have hired someone to do any allegedly required dirty work, a person who used Google Earth to go to the wrong house?
This story brings to mind the even more recent case of the alleged murder of Rodrigo Diaz. His friends claim that his GPS had led him to the wrong house.
The owner of that house allegedly became annoyed or threatened by the presence of Diaz and his friends. This resulted in Diaz being shot in what lawyers for the accused, Phillip Sailors, say was a case of self-defense.
The jury in the trial of Eric Koula believed there was enough evidence to convict him.
Others look at the evidence they see on Google Earth and still have their doubts.