Investigators in white hazmat suits carried out several large brown paper bags of evidence and a large carpet from the Kansas City, Mo., home of missing 11-month-old baby Lisa Irwin.
The 17-hour search allowed for glimpses into the types of evidence collected and the tight-lipped investigation's techniques.
This was the first search in the case that was conducted without the consent of Baby Lisa's parents, Deborah Bradley and Jeremy Irwin. Investigators obtained a search warrant from a judge.
"We felt [that] this time, since [Bradley and Irwin] had retained an attorney, to go to a judge to make sure there was no confusion over our legal right to be there," Kansas City Police Department Capt. Steve Young told ABCNews.com.
Young could not get into details of what may have been found in the search that stretched into the early hours of Thursday morning, but he did comment more broadly on the progress of the investigation.
"This has been an ongoing case for weeks now, and it's safe to imagine in the course of it what we've learned -- new pieces of information that are pushing the case forward," Young said.
The search team at the house spent hours combing the yard with rakes and shovels. In the afternoon, bomb and arson trucks arrived with additional equipment, including machinery used to x-ray solid objects and, possibly, walls.
"They were looking for items -- materials, whether they be generic like DNA, hairs and fibers, [or] organic like leaves, dirt -- to compare to something they have," Brad Garrett, an ABC News consultant and former FBI special agent, told "Good Morning America" today.
Police searched the home extensively in the days immediately following Lisa's disappearance with scent canines and FBI agents in hazmat suits, and police officers attempted to re-create the window break-in scenario the parents described.
While authorities are mum on what caused them to return to the house more than two weeks after Lisa disappeared from her crib, Garrett said there would have to be a new component to the case in order for a judge to authorize a search warrant.
"You have to have something new, something that just has occurred to convince a judge to allow you to go back in a house with a search warrant," Garrett said.
Private investigator Bill Stanton, who has been in frequent communication with Lisa's parents, spoke to "GMA" today about their reaction to the search.
"My interpretation is that they welcome it," Stanton said. "They want this to be uncovered."
Stanton also made a distinction about his role in the investigation.
"While I'm working with the family, I'm not working for the family," he said. "If I get information that leads to their guilt, so be it. And I told them so."
He said his instincts still lead him to believe that it was someone from outside the home that took Lisa.
Stanton revealed that the anonymous benefactor that put him on the case is a woman and that this mysterious figure is not the same person who is paying for the legal services of well-known New York defense attorney Joe Tacopina.
In the past two weeks, police have cleared more than 550 tips and leads that have not led to any suspects or hard leads.
The anonymous benefactor paying Stanton is offering a $100,000 reward for Baby Lisa's safe return or the conviction of whoever took the little girl.