Kansas City, Mo. ? An FBI cadaver dog reacted to the scent of a dead person inside the Kansas City home where a baby girl disappeared nearly three weeks ago, and investigators discovered soil in the backyard that had been “recently disturbed or overturned,” police said in a court document released Friday.

The affidavit, filed earlier this week in support of a search warrant targeting the family’s home, also stated that the girl’s mother, Deborah Bradley, “made the statement she did not initially look for her baby behind the house because she ‘was afraid of what she might find.'”

Those details and others in the affidavit, publicly released for the first time Friday, led to a daylong search Wednesday of the family’s home, where the parents say then-10-month-old Lisa Irwin must have been snatched in the middle of the night as the mother and two other boys slept. Bradley and the baby’s father, Jeremy Irwin, reported the girl missing on Oct. 4 and have denied any role in the disappearance while insisting police have pointed the finger at them.

‘Scent of a deceased human’

The affidavit stated that an FBI cadaver dog taken into the house Monday indicated a “positive ‘hit’ for the scent of a deceased human in an area of the floor of Bradley’s bedroom near the bed.”

The FBI dogs, which often are used at both disaster and crime scenes, are trained “specially to recognize the scent of decaying, decomposing human flesh,” retired FBI special agent Jeff Lanza said Friday.

“That can be the scent of an actual body decomposing, or residual scents after the body is no longer there,” Lanza said.

Dr. Edward David, a deputy chief medical examiner for the state of Maine and co-author of the “Cadaver Dog Handbook,” said that when a body is left in one spot for several hours, cells are left behind. They continue to decompose and create an odor, giving the dog scents to detect.

He said that while trained dogs may fail to detect the smell of human decomposition about 30 percent of the time, they generally don’t alert when nothing is there. One exception is when human waste is present.

Joe Tacopina, a New York lawyer hired by a benefactor he has not identified to represent Bradley and Irwin, said the dog could have detected “a dirty diaper or 10 other non-human-remains items.”

But granting that cadaver dogs are trained chiefly to detect decomposing flesh, “There’s really no scenario where this baby, God forbid she was dead, would have decomposed in that short a period of time,” Tacopina told The Associated Press in a telephone interview Friday night.

The court document also indicated police felt they needed handheld digging tools after an investigator noticed dirt in a garden area behind the home appeared to have been “recently disturbed or overturned.” During Wednesday’s search, investigators could be seen digging behind a shed in the backyard.

Other revelations

Among other revelations in the affidavit:

• Officers searched all rooms in the house and the basement after being called to the home Oct. 4. Officers sought evidence but because the parents said the baby had been abducted, the only areas extensively processed for DNA and fingerprints were the baby’s bedroom and possible entry points.

• The parents had told police that three cellphones were missing. The affidavit said a phone had since been found in a desk drawer, but that phone wasn’t one of those reported missing. The missing phones haven’t been found.

• Interviews with people involved in the case revealed “conflicting information for clear direction in the investigation.”