But we’re they at the scene or did they just bump into someone or something that was there?
replyThat's something that would have to be addressed at the trial by the defense attorney raising challenges.
replyIf the DNA is present, it's present - barring any procedural mistakes by the forensics technicians (mislabeled sample, dirty lab equipment, didn't follow manufacturers instructions, etc). Or deceit by one or more members of the forensics team to implicate the suspect.