Investigators are executing a search warrant today at the Kansas City family home where 11-month-old Lisa Irwin vanished from her crib on the night of Oct. 3.
Kansas City Police Department Officer Capt. Steve Young told ABCNews.com that investigators will be in the house "pretty heavy today." Police have blocked off the road in front of the house and instituted a no-fly zone over the neighborhood.
Previously, the family had allowed voluntary searches of the home.
Lisa's parents Deborah Bradley and Jeremy Irwin have not stayed at the house since her disappearance. They have been staying at a relative's home.
Young would not comment on the details of what brought police back to the house with a search warrant two weeks after Lisa disappeared, but said, "As the investigation progresses, I'm sure we continue to develop information that causes us to take different and new action."
Police obtained a search warrant for the house late Tuesday night and have had constant police presence on the property since then keeping everyone away from the house, including well-wishers with teddy bears. Investigators are expected to be at the home all day.
Brad Garrett, an ABC News consultant and former FBI special agent, told "Good Morning America" today that police would need to new information in order to secure a search warrant from a judge.
"They would have to show a judge that they have new information," Garrett said. "Now, what could that be? It could be potentially a tip. It could be be potentially a physical piece of evidence that they found."
Police searched the home extensively in the days immediately following Lisa's disappearance with scent canines, FBI agents in hazmat suits and police officers attempted to re-create the window break-in scenario the parents described.
FBI spokeswoman Bridget Patton told ABC's Kansas City affiliate KMBC that no specific tip or lead brought them back to the Irwin home, but detectives are searching for anything to move the investigation forward.
In the past two weeks, police have cleared over 550 tips and leads that have not led to any suspects or hard leads.
Suspicions have escalated surrounding Bradley and Irwin this week with the news that the couple have not submitted to an interview with detectives for the last 10 days to answer questions about things "they might only know," police said Tuesday.
Bradley's story seemed to change this week and she has admitted to being drunk that night, possibly even blacking out.
Kansas City Police Capt. Steve Young expressed some frustration today with Bradley and the girl's father, Jeremy Irwin.
"There are things the detectives need to flesh out with the parents that only they would know and we no longer have that opportunity to sit down with them," Young told ABC News this afternoon. "We have not had an unrestricted conversation since Oct. 8th."
"And that time, and previous times, there came a point when Deborah became uncomfortable and stopped the questioning," Young said.
Young conceded that the parents have spoken with detectives since Oct. 8, but only to clarify information about tips that have come in.
He said the contact has been limited to conversations about details that need to be cleared up such as, "Do you know this person?"
"We strongly believe that that parent's cooperation and involvement is critical [in finding Lisa]," Young said.
Police have previously accused the parents of halting their cooperation, although the parents have insisted they continue to answer officers' questions. Today's comments by police were more specific.
Young also bristled today at criticism by Joe Tacopina, the high powered defense lawyer who is now representing Bradley and Irwin.