May 2, 2008 -- "20/20" co-anchor Elizabeth Vargas recently spoke with former FBI Special Agent and profiler Brad Garrett, an ABC News consultant, who discussed the details surrounding the disappearance of Madeleine McCann.
Reports said the Portuguese police arrived on the scene soon after Madeleine vanished, and left soon after, a fact Garrett called "unusual." Garrett, who has worked on several high-profile missing persons cases, including that of Chandra Levy in Washington, D.C., said investigators would typically form a "command post right inside the resort. You start collecting information, and everything comes back to a lead detective in a room, and that's how you go through the information. You prioritize what needs to be done. ... You want to be right in the middle of the action so you can make snap decisions as to what should be done at any given time."
Garrett added, "You put people in places like airports, ports for boats" and you secure the scene as well as the resort so that everyone coming in and out is vetted.
From his experience, Garrett said that typically, in an investigation like this, the police would obtain and review surveillance tapes from the resort and any surrounding areas. And police would generally have a set team of law enforcement in place from the very beginning.
"Every case that I've worked like this you usually have a case agent, an FBI case agent and a lead detective," he said. "They sit right next to each other, and they work from that location, and everything comes back to them to make decisions on what should be done."
It would have been helpful in the McCann case, Garrett said, to know which cabs arrived at the resort. Additionally, he said police should have spoken with the entire staff at the resort to figure out if there were any people working there who had a history with missing children. "People get hired and there's limited background done on them," he said.
"You want to keep calm," he said. "The last thing you want is for them to get excited. They see this hysteria, that's one side of it. The other is some of these guys get kicks out of watching parents suffer on camera."
Garrett said Madeleine could have been taken by someone looking to adopt a blond 4-year-old attractive child. In these types of scenarios, "they actually have somebody go out and look for the child," Garrett said. Adoptive parents also might go to an agency that's unscrupulous and abducts children, he said.
But how could someone take Madeleine from her room without anyone hearing her cry or making noise?
Garrett said there are a few explanations. The McCanns have said that their children sleep quite soundly and that the twins apparently slept through the abduction. They even slept through the police coming into the room, the couple said.
Madeleine might have known her abductor, Garrett said. Somebody might have independently befriended her, possibly someone who works at the resort, he said.