Authorities used a search warrant Wednesday to block baby Lisa Irwin's Kansas City home from her parents, Deborah Bradley and Jeremy Irwin, and to further scour the home and yard with shovels, rakes, and ladders. Baby Lisa went missing from her crib 16 days ago, according to her parents.

FBI agents, Kansas City police and the Missouri National Guard used yellow tape to mark off a perimeter around the Bradley-Irwin home, according to The Associated Press.

A Missouri judge granted investigators a warrant Tuesday to search baby Lisa's home and to keep Bradley and Irwin away from the home, Sergeant Stacey Graves, a Kansas City police spokeswoman told Reuters.

Although investigators have already searched the home with Lisa's parents, FBI agents and police are using this opportunity to search the home without Bradley and Irwin. No one can enter the house until the investigation is complete except police authorities.

We have a warrant for the house, city police spokesman Capt. Steve Young told The AP early Wednesday, but he did not explain the reason for the warrant.

I don't know why a warrant is needed. They can go in and out any time, Joe Tacopina, the family's lawyer, told The AP. They have had unfettered access because we want answers.

The warrant will also allow police to seize evidence from the home that they could later use in a trial if necessary. Authorities are looking for DNA, blood, fingerprints, and other evidence that may be helpful in figuring out who was involved in baby Lisa's disappearance.

On Tuesday, FBI, investigators and National Guard members searched the wooded area around the Bradley-Irwin home for the fourth time.

They also investigated a fire that had occurred in a dumpster about an hour and a half before Bradley and Irwin reported Lisa missing, NBC reported.

Attention has once again turned to Deborah Bradley, baby Lisa's mother, who has changed her story a few times during the investigation.

Bradley admitted that she had been drinking heavily the night Lisa disappeared and says she may have even blacked out. She claims she did not see the baby after putting her to bed around 6:40 p.m. This time is four hours earlier than Bradley initially told the police and she gave no excuse or explanation for her mistake.

I was the last one with her, a tearful Bradley said in an interview with NBC. And from judging on how the questioning went, that's kind of a fear that I have. And the main fear with that is, if they arrest me, people are going to stop looking for her. And then I'll never see her again, and I'll never know what happened.

I had absolutely nothing to do with it, Bradley continued. It's a waste of time, money, energy and focus and people should be looking for [Lisa].

In the past 10 days, however, baby Lisa's parents have not cooperated or spoken with police.

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.

In the past two weeks, police have investigated over 550 tips and leads, but do not have any major leads or suspects.

Irwin, an electrician, maintains that he returned home from work around 4 a.m. Tuesday to discover baby Lisa missing.The parents say they searched frantically for baby Lisa early Tuesday morning, but found only the front door unlocked, a window opened, house lights turned on, and three cell phones missing.

Baby Lisa Irwin, nicknamed pumpkin pie, is described as white, with blond hair and blue eyes, about 30 inches tall and weighing 26-30 pounds. The family says that she was last seen wearing purple shorts and a purple shirt with white kittens on it. The family has released videos of baby Lisa hoping it will spread her image and keep attention on her case.

If you have any information on the girl's whereabouts call the TIPS Hotline at (816) 474-TIPS.