Baby Lisa Irwin's two older half-brothers, both of whom were in Deborah Bradley and Jeremy Irwin's family home the night Lisa disappeared, will be interviewed by investigators Friday and provide DNA samples.

Child specialists spoke to the two brothers Oct. 4, the day after baby Lisa was allegedly taken from her home, but the boys, Michael, 5 and Blake, 8, have been kept from police since that day.

This will be the first time we've had a chance to interview them since then, Kansas City Police Officer Darin Snapp told ABCNews.com Wednesday. We have not been allowed access to the children until [parents Bradley and Irwin] agreed to bring them in this Friday.

We are expecting to collect DNA samples, Snapp said. It will be very non-intrusive, pretty much just a Q-tip swab.

Police claim they want the DNA samples from the two brothers to compare it to the unidentified samples they have taken from the home, the Kansas City Star reports. The brothers' DNA is necessary so they can eliminate certain DNA samples from the home and then see if there are any unknown DNA samples that might indicate an intruder was present the night of baby Lisa's disappearance.

Snapp said that the interviews on Friday will be conducted by child specialists and there will be no investigators or detectives in the room.

The interviews will happen with... special certified forensic interviewers who are specially trained to interview children, Cyndy Short, one of the attorney's for baby Lisa's parents, told Fox News. Snapp confirmed that there will be no investigators or detectives in the room.

Not an interrogation, Kansas City Police Capt. Young said. They are kids, after all.

Investigators also want to interview the boys to see if they remember anything that might be able to help find their younger sister, Snapp said.

Bradley told NBC last week that the boys heard noises the night Lisa vanished, but she was uncertain of the details.

They said they heard noises [the night Lisa disappeared], Bradley said. I don't know if that was before we went to sleep or after. Bradley said she has not pressed the boys on the issue because she didn't want to put them through anything else.

The night baby Lisa disappeared her two brothers were sleeping in Bradley's bed.

Despite Bradley and Irwin allowing baby Lisa's brothers to be interviewed, police still maintain that the family has been uncooperative as they are refusing to answer tough questions and have refused to be interviewed separately since Oct. 8.

We need them to sit down apart from each other, with detectives, and answer the tough questions detectives have for them concerning what they may or may not know about anything, who came and went [the night Lisa disappeared], Kansas City Police Capt. Steve Young told ABCNews.com. There's a whole list of things that they may know.

Young claims that while the family has allowed police to search their home five times and has answered preliminary questions, they still have not done everything they can to help authorities.

The bottom line is detectives need to sit down with them unrestricted and they need to answer questions that we need answered, he said.

Joe Tacopina, one of the family's lawyers, does, however, have restrictions on the kind of conversation he will allow baby Lisa's parents to have with the police. He claims that police have unfairly targeted Bradley, baby Lisa's mother, which doesn't build good faith in them. He says baby Lisa's parents are only willing to speak to police if they do not presume guilt before having sufficient evidence.

It really is maddening to me to listen to this police spokesperson come out there, and instead of informing the public -- and more importantly the family -- about leads and the status of the investigation and the manhunt, [Young] comes out and makes these statements, Tacopina told Good Morning America. And, quite frankly, [the parents have] done everything they've been asked to do...They have nothing to hide. They want answers.

Bradley and Irwin's lawyers, Tacopina and Short, believe police should focus their investigation on the man seen by three eyewitnesses carrying a baby in a diaper the night baby Lisa disappeared.

Police, however, have refused to comment on the surveillance video found at a Kansas City gas station showing a man leaving a wooded area two miles from baby Lisa's home the night she disappeared. They also declined to comment Tuesday on the eyewitness reports, CNN said.

In order to find justice, law enforcement must remain open and unbiased, Short told PEOPLE Magazine. I'm not inside the investigation. We just hope there are many things going on that we can't see. We have to hope that those that we are allowed to see aren't the only things happening in the investigation.

Authorities have received over 975 tips and have cleared nearly 800. There are still no major suspects or leads in the investigation.

Hope is what they're living on, she says of the parents. They are drained of strength at times, and there's really no road map on the journey they're on. They're just hoping and praying that someone will make that one tip.

Baby Lisa's parents claim the 11-month old mysteriously disappeared from their home late Monday night or early Tuesday morning nearly three weeks ago. Irwin, an electrician, maintains that he returned 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.