The poor thing is said to have died of dehydration as although it was apparently under weight when brought in (due to most likely being a racing dog dumped by owner), it did not appear to be in ill health.
Greyhounds rarely bark and so it's good nature may have been it's downfall.
The SSPCA are launching an independant enquiry and the police officers involved may face animal cruelty and abandonment charges if found responsible.
The officer who took the dog in was apparently from another station and not familiar with the Dalkeith one and so logged the details but did not pass on the information to the correct people. So he would not have returned to the station after his one (must have been cover) shift and the Dalkeith based officers would have no idea.
I know. I'm guessing that anyone on this forum is a big animal lover and we are all upset about this story. I just can't believe they could get it so wrong.