I hate to say it, but "probably" is the only thing that cuts it. This is not a "beyond a reasonable doubt" case. It is a "preponderance of the evidence" case.
"In legal terms, a preponderance of evidence means that a party has shown that its version of facts, causes, damages, or fault is more likely than not the correct version, as in personal injury and breach of contract suits. This standard is the easiest to meet and applies to all civil cases unless otherwise provided by law.
The concept of “preponderance of the evidence” can be visualized as a scale representing the burden of proof, with the totality of evidence presented by each side resting on the respective trays on either side of the scale. If the scale tips ever so slightly to one side or the other, the weightier side will prevail. If the scale does not tip toward the side of the party bearing the burden of proof, that party cannot prevail."
http://courts.uslegal.com/burden-of-...-the-evidence/
Circumstantial evidence is still evidence, and when it is enough to tip the scales in one direction or another, then it prevails.
Aaron Hernandez was convicted of murder based upon "circumstantial evidence."
EDIT: Aaron was a patriot too, wasn't he??