Officers headed to the back of the home with shovels, rakes and a ladder. Some could be seen digging behind a shed in the yard. No law enforcement officials would comment on the nature of the latest search.
Just before noon, three investigators left the house carrying brown paper bags and clear plastic bags and took them to the vehicles parked outside. Kansas City police spokesman Capt. Steve Young said he could not comment on the contents.
Young said investigators were bringing in a bomb and arson truck to assist in the search. He said there were no indications of explosives in the house. Some bomb detection devices use X-ray technology to scan solid objects to reveal items concealed within. An AP reporter saw investigators carrying at least a dozen thin, black rectangular sheets away from the home.
Lisa Irwin was 10 months old on Oct. 4 when her parents reported her missing. Her father, Jeremy Irwin, an electrician, said he returned home from a late shift to discover the lights on, a window tampered with, the front door unlocked and Lisa gone. The baby's mother, Deborah Bradley, and Lisa's two older brothers had been asleep elsewhere in the house. Bradley has admitted she drank heavily that night and may have blacked out.
The parents insist their baby was snatched by an intruder.
Police, FBI agents, officers from area law enforcement agencies and the Missouri National Guard have already searched the family's home, neighborhood, nearby wooded areas, a landfill and abandoned homes. Police have refused to discuss any evidence gathered in the searches, saying only that they remain without a suspect.
"We have a warrant for the house," Young told The Associated Press. He did not explain why a warrant was necessary. There was no indication that the family has tried to block investigators' access to their home, which has already been scoured by FBI agents with dogs.
FBI spokeswoman Bridget Patton said the search is not based on any sort of tip. Patton said they were restricting media access because agents are using a procedure involving dogs that they didn't want to be recorded. She declined to elaborate.
Young said all previous searches of the house have been conducted with the family's consent. The warrant prevents anyone except those involved in the investigation from entering, meaning family members -- who have returned home from time to time to collect clothes and other belongings -- may not go back inside until the search is over.
The family's lawyer, Joe Tacopina, told AP early Wednesday that he had not heard about the warrant except through media reports.
"I don't know why a warrant is needed. They can go in and out any time," Tacopina said. "They have had unfettered access because we want answers."
He said the family hasn't been back to the house in the past couple of days because they don't want to interfere with the investigation.
The Federal Aviation Administration established a no-fly zone over the search area effective until 5 p.m., agency spokesman Tony Molinaro said. He characterized the zone as a safety precaution and said it had been requested by law enforcement. Similar restrictions were introduced during a search of the area Tuesday.
Much attention has focused on a rash of recent TV interviews the parents have given in which Bradley admitted she had consumed several glasses of wine the night that Lisa disappeared. She also told NBC that she did not see the baby after putting her to bed at about 6:40 p.m. -- roughly four hours earlier than the time she originally gave police. She didn't explain the difference.
Tacopina has said Bradley's candid words indicate the parents have nothing to hide.
Bradley has said she expects to be arrested in her baby's disappearance.