But if it goes to prove the truth of what it’s asserting then that might be hearsay and inadmissible unless it falls under an exception that lets it in. For instance, if a witness testified that Ned told him that Bob was going to bomb the building, that’s probably not admissible since what you’re trying to prove is that Bob did it. I can’t think of a good example that fits here – maybe if the printout was a copy of the threat and said “Bombs away! Signed, Bob.” But again, there are lots of exceptions that could let something like that in.

The test printout is then examined to see if the time, date and serial are in accordance with the evidence from the bomb threat note received. If they are then there is a clear evidence that the person arrested is the supposed bomber.

Any evidence can be tampered with, it’s the degree with which it may not be credible that matters. If standard procedures are taken, why would it be less admissible than any other piece of evidence?