-- where is baby Lisa that question has sparked an agonizing drama a national search. For a missing Missouri -- that intensified today as a lawyer for the infant's parents. Came down hard on police... See More
-- where is baby Lisa that question has sparked an agonizing drama a national search. For a missing Missouri -- that intensified today as a lawyer for the infant's parents. Came down hard on police not for their failure so far cracked the case. But for their conduct toward his clients which He calls unimaginable. Police replied that these parents. Are not doing all they can to assist in the search meanwhile. They be Lisa has been missing three weeks as of today here's ABC's Matt got. Over the past three weeks Kansas city police and FBI had been chasing literally a thousand -- across the country. To try to find BB -- Missing eleven month old girl. But they keep coming right back here. The house on north -- and focusing their attention on BP Lisa's parents. Deborah -- -- and Jeremy Irwin seen here trembling with grief that a recent vigil for baby Lisa. Earlier today on Good Morning America a family attorney -- Kansas city police for their treatment of its clients. The mother who's missing -- federal babies and now sitting on what trembling as the -- -- my -- one. -- within an hour of that the the leases at their current -- are interrogating her and accuse her murder I mean just imagine they've done everything they've been asked to do that consented to every search they've been -- consent to. But running short on viable leads and patients the police counter that Deborah Bradley jury -- are not cooperating. Specifically the couple has refused to be interviewed separately by police since October 8 nearly three weeks ago. Authorities taken a step farther saying -- -- would likely have the answers that could lead police to baby Lisa. Answers that they say any parent should know about -- China their whereabouts -- -- Within the attorneys have told ABC news exclusively. That they will allow police to re interview Bradley and win suns. End to take DNA swabs the boat for home tonight BB Lisa vanished and both were interviewed by child specialist that day. Police have searched the house five times last week police say. A cadaver dogs smelled human decomposition on the carpet. In the parents venture. I'm giving permission to walk through the house the family's attorney Cindy short downplayed its importance in an exclusive tour of the house over the weekend it was a visit to a house that seemed almost -- The leases diapers still strewn floor walls -- -- the window -- freshly fingerprinted. And that's -- Much had already been taken from Lisa's room. They took that crib sheets that very first time -- with the consent and here. But in that critical the master bedroom. Dogs allegedly smelled death. Car remained had -- He dog alerted. On one side or the other the bed that -- noticed you walk around all the carpeting is intact it was not passed out. Present and that's correct. But so far no risks -- could meet the suspect's name there's no question that the authorities are looking at the parents as possible -- I think they're also looking elsewhere they're looking at the possibility of an intruder. I think that's what's making this investigation. So frustrating is that people would just don't know what to me. And in -- dean of tips and sightings 800 already fully cleared by police in the FBI investigators are retracing their steps. People are being honored in a picnic or how well they -- -- -- -- who -- this. Go back to Mike talents motorcyclist. Who claims to spotted a recent carried by a man down the street just a few miles from him peaceful. They should be. Paper was six pictures. -- did you pick one out opportunity. And picked. -- David Schulman victims. ABC news obtained the picture of that -- -- alert. It has been questioned by police multiple times we showed it to another eyewitness who lives just three houses away from -- Lisa's parents. -- -- claims to have seen the same thing several hours earlier a lone man walking with a nearly naked baby. The middle of the night here on -- there. Now I don't renting -- -- similar citing very different -- I know that He was tall and slender. As far as his head we -- was involved think we've seen and shiny and. Just have to remember that eyewitness testimony. Is never -- certain. As it seems and it can sometimes be just flat out on -- Still no suspects and no hard evidence. Parents continue to shy away from the cameras all that remains is the followed the mystery seemingly as impenetrable as it was. The night -- Leeson disappeared. For Nightline I'm Matt -- in Kansas City.
This transcript has been automatically generated and may not be 100% accurate.