Reading the online reports yesterday and today about this German suspect, one thing that jumped out for me was regarding his telephone records at the time Maddie was murdered by her parents reported as being abducted. The reports claim his full telephone records from that time have him in the vicinity/town on days prior to and on the day itself. Compelling, if they can tie his geographical locations with his specific movements.
If i remember correctly, was there not an unexplained void in McCann's telephone records where his phone had been switched off for a number of hours ?? I seem to remember the last known locations, pre-switch off, had him heading away into the remote wilderness inland of Praia. His tennis bag mysteriously went "missing" around the same time.
With modern, updated technology, i'm sure if someone wanted to revisit the telephones aspect, then maybe McCann's records and movements would go some way to maybe nailing this one way or another.