There have always been questions about reliability (of) other types of evidence -- eyewitness testimony or circumstantial evidence. Once they see the DNA evidence, there's no question. You are either guilty or not guilty.

In O.J., the defense raised the questions that the evidence was kept in the trunk of the car, collected without officers using gloves, et cetera.

Circumstantial evidence shows that someone took the knife from the scene.

Some circumstantial evidence is very strong as when you find a trout in the milk

From what I have seen, there seems to be some circumstantial evidence which might lead one to think that some of the defendants at least may be guilty, I haven't seen anything which would enable a conviction to be brought.

Take it all together and it certainly seems like circumstantial evidence linking Nichols to the robbery, if in fact a robbery occurred.