What's obvious to you isn't necessarily obvious to those who work in the criminal justice system. An obvious diligence in most countries is to have a police elimination database to rule out innocent contamination. So every police officer provides a sample fingerprint upon joining and in cases such as this one where a fingerprint was unidentified at soc a quick simple search is made to confirm whether or not it matches an officer present before looking for answers across the globe. Another obvious diligence would be for officers to wear gloves.
What does Portugal's police training manual state? How do Portugal's courts handle the above?
That's up to YOU to make such a case re Portugal 2007. And for your 'most countries' claim, which you repeat without any supporting evidence. While you are at it, please provide supporting evidence that in 2007, it was the norm for officers responding to a missing child call to wear gloves.
Frankly, you appear to be on a mission to support your assertion in the face of the facts.
The Trovão response clearly shows Portugal did NOT have such a facility in 2007.
Hopefully, your theory is more robust than your current argument.