Identify time of recording from mains hum (UK)

[John Gray]

This might be of interest to the Criminal Mind (you know who you are...!).

Another video by the ever-enthusiastic and interesting Tom Scott about The Hidden Background Noise which could Catch Criminals.

[StuartR]

That's brilliant John

[BobH]

Interesting but one wonders if distance from the mains hum or if blocking such as produced by walls, etc. would make the forensics useless.

[ChrisGreaves]

This might be of interest to the Criminal Mind (you know who you are...!).

That Hertz!

[stuck]

Featuring an expert from the University of York, not that far from me. Better be on my best behaviour.

Ken

[ChrisGreaves]

Interesting but one wonders if distance from the mains hum or if blocking such as produced by walls, etc. would make the forensics useless.

I believe that walls, distance etc make no change at all to the argument.
The argument, as I understand it, is that the forensics are analyses of signals, coming up with a probability that "things match".

My understanding of juries (ref half of John Grisham's novels) is that juries are all too easily swayed by a chart of some sort, so the dark-smudge line shown in the video shots of the laptop monitors is another nail in the coffin for the prosecutor.

My understanding of forensic DNA is that likewise, a match is rated at "one in so-many million"
Fingerprints, likewise, and iris scans. And GPS signals. It is stated that a mis-match is "extremely unlikely", but never that it is impossible.

In the case of the frequencies, as stated in the video, the aim is not so much to prove that "John Gray was at the scene of the crime" but rather that "we can find no break in the sequence, so we are certain that this recording was not edited".

My guess is that the forensics would be close to useless in the ghost town of Kollyanobbing, fifty miles NNW of Southern Cross in Western Australia, but spot-on if I was standing underneath one of the several Hydro right-of-way towers in Toronto Ontario.

Your partner in crime
Chris

[ChrisGreaves]

Featuring an expert from the University of York, not that far from me. Better be on my best behaviour.

But Ken!
YOUR best behaviour might not be good enough!
We have already been told that mine is not
Cheers
Chris