Michael Usry Sr. was ONLY ONE ALLELE away from going to jail for the rest of his life!!
His father is the case you should be thinking about.
You think they would have paid attention to any alibi short of him being on live national TV or in prison at the time of the murder?
Part of the "validity" of DNA matching is that it is generally used as a method of confirmation: "Bob was seen have having an argument with the victim 20 hours before the body was found, He was having an affair with the victim's wife, there is only one chance in three billion that a random stranger has the same DNA profile...."
This is vastly different from collect and type the DNA. look in some databases. Then prove the person did the deed! .