Because they were boozing down at the bar instead of looking after 3 children under 4. Because it wasn't just their reputations - it was also the repuatations of the other doctors there who were may or may not have been complicit in any accident (if an accident did occur).
Correct - one dog found blood - but in very small quantities because the floor had been throughly cleaned - the other dog smelled cadaverine.
Cadaverine is a foul-smelling compound produced by protein hydrolysis during putrefaction of human tissue.
DNA was found in their hire car boot - but...
What I have never understood about this case is that the most likely scenario is the one least reported and investigated by the press, namely that that a young unattended child woke up in the middle of the night and went looking for her parents in the villa. Upon not finding them (they were out...