Experts discovered this 'partial footwear mark', believed to be from a size 5 or 6 shoe, just outside the bedroom. But significantly, no traces of blood were found around it.
Scientists at the Forensic Science Service laboratory in Birmingham found that there is a 'moderate' chance that the blood belonged to Madeleine. But the results are inconclusive.
'It is quite possible, therefore, that the blood had been picked up on the sole of the shoe from outside the apartment, from literally anywhere,' said a source close to the investigation. Link