The information on this case was pretty sparse, but from what I could see there were a few interesting points:

  1. Only one child was taken.
  2. The child was very young.
  3. It’s a possibility that the McCanns may left their children in what they considered a safe and secure place more than once.
  4. Despite searches nothing was found, with few leads and little forensic evidence.
  5. There was no indication that an abduction ring was operating in the area, as no other children seemed to be missing around that time.
  6. No children shortly before or since seem to have been taken in the area.
  7. Local people who had suspect pasts in this area were probably checked first by the police and probably didn’t fit their profile.

The problem was so very little information was released, so clues to what had happened would be nowhere near enough to jog anybody’s memory.

There seems to be a main set of possibilities for the abduction:

  1. If there was a sex offender who took her. Point 7 would have probably given some indication if one was present in the area, and 6 would suggest this was a one off. The various police teams would have investigated closely any previous offenders, and if one did abduct and kill her, they rarely have no prior similar offences and stick at just one. Neither has happened, and such a person’s usual psychology usually would mean that someone of Madeline’s age would not normally be of interest to them. Most choose a victim mainly to participate in such an intended crime.
  2. The absence of any obvious or known abduction ring operating in the area suggests this is unlikely. There were three children there, and an organised abduction ring would probably take all, as they would be worth more. Quickly spiriting away all three without trace would not be much harder that just one. There was no hint of any transfers, and a single person would be severely inconvenienced. So it’s likely that there had to be more than one person involved, so taking them would also not give the risk that they had been seen by the others, and a clue given to their identity. Also it was a hard task, random children at other times would be much easier for such a group.
  3. Kidnapping for ransom was a possibility, but no ransom or calls were made.
  4. This suggests Madeline was targeted. There was some reason that she was chosen and not her siblings. The key is figuring out the characteristics that differ from the other children.
  5. This is a very serious and a risky crime so would not be undertaken lightly, and the lack of any evidence or signs suggests it was planned. It could be that it was just an opportune crime, but the risk is great unless there is an equal benefit and the fact the other children were not abducted suggests a simgle person and a single abduction. If for money, then the person knew where they would get a return as nothing else was retported missing, that would normally happen in a burglary. This still suggests an abduction to order.
  6. If the child was targeted, the person who instigated it probably met Madeline at a previous time, and most likely familiar with her parent’s routine. Possibly having watched for a while. A person who was keeping an eye on her parents may have checked to make sure they were absent, by doing something like ringing the restaurant.
  7. It takes a lot of nerve and drive, possibly compulsion to go ahead with such a risky plan, even if you get someone else to help you. And how do you justify to yourself or another person that the abduction is not totally wrong? This suggests that together with the targeting, something like a maybe a misguided loyal couple was involved.
  8. There have been a number of cases where a woman who has lost her child chooses to abduct a child of a similar sex and age, especially if the child resembles hers. A doting husband dismayed at his partners mental deterioration, may justify himself in helping his partner find a quick cure, weighing up the risks and alternatives.
  9. If the meal was not the first time that the McCann’s had done this, they may even justify in minds the actions on them not deserving to keep Madeleine.
  10. Such a couple would probably not just be holidaymakers, as it’s unlikely that they would decide to go on holiday with one or both of them in this condition. This would suggest they have a local residence, to start the plan from and to hide if necessary. Most likely a time-share or owner.
  11. At three Madeleine would be speaking English, so any non-English couple doing the abduction would immediately be suspect, if Madeleine was seen in another country. The likeliest abductors would probably therefore be English speaking as a first language.
  12. They probably left the area directly after the abduction, but not before they disguised and sedated Madeleine. Getting across borders would be a problem, but not if they had their lost child on a passport, but not removed. The likeliest escape route would be driving with a sleeping child in the back heading for something like Madrid, then the south of France, ending up on a car ferry to the UK.
  13. The local residence in Portugal, as could their home in the UK if they have one, could be sold at a distance, not returning, staying in a local rental until a house bought in an area of the country where they are not known. Alternatively emigrating to mid US where they would stand out only to local people, but remain pretty anonymous.
  14. There is chance that if Madeleine in the future has a DNA test, then her link to her real parents may be discovered.

The whole scenario of the crime suggests that it was committed to order and not just an opportune one, and would she would stand out except in a Northern European or Northern American area.