If it is practice to use two VRD teams, there must be a reason for that and I think it must be for verification particularly in criminal cases.
Also for justification to initiate an expensive course of action which is not necessarily to uncover criminal activity ...
This Sept. 22, 2014 photo shows an old well building in front of a home in Meadow Valley, Calif. The Plumas County Sheriff's Department said three cadaver dogs have alerted on the well, which is near the former home of Mark Wilson. Wilson was 13 went he disappeared in 1967. The sheriff's staff is trying to find funding sources for the nearly $100,000 it will take to excavate and reinstate the site.
Read more: http://www.dailymail.co.uk/wires/ap/article-2797589/Cadaver-dog-work-accepted-cops-courts.html#ixzz3at7QUFCC
Back to the Welsh dogs. I think two dog teams are used to search and for corroboration.
If one VRD alerted and the handler recognised it as a trained response the other VRD and handler would be brought in and the determination made whether it would be necessary to follow up with forensic examination of the area.
I never saw the dogs working in tandem ... which doesn't mean that did not happen ... but surely it would make sense to cover the large area with both dogs working to their own grid with perhaps an overlap to ensure nothing was missed.
There was nothing to indicate, on the ground, that the mound was worked in grid fashion. It might have been, just nothing to indicate it.
SY said 41 anomalies investigated of which 3 were outside the mound. So the process APPEARS to have been - identify anomaly - then investigate.
When they went into specific areas they would mark the perimeter, strim the weeds, then conduct a search.
There appeared to be vast tracts that were not searched at all, however, I was not there for vast chunks of time, so I could well be wrong.
I have wondered why they chose to lift some drain covers rather than others.
Whether the dogs in this search alerted or not seems to me to be 100% on-topic. Would the 2014 dogs have alerted after 7 years? When Amaral was told the dogs never made a mistake, what was he supposed to believe?
There's black. There's white. And there's all the grey in between.