It's been more than two weeks since New Canaan mother of five Jennifer Dulos disappeared, and nearly a week since her estranged husband and his girlfriend were arrested for tampering with evidence and hindering prosecution.

Detectives have been scouring for clues in New Canaan and the Farmington-Hartford area, where Dulos' estranged husband lives and works.

Private investigator Don Kleber tells News 12 that if law enforcement can get Fotis Dulos' girlfriend, Michelle Traconis, to cooperate in this investigation, then she may be able to lead them to the victim or key physical evidence.

"I think they're doing everything they can with regard to attempting to locate Jennifer," says Kleber, who is with Blue Hawk Investigations. "The biggest challenge is the dump site, the trash site. The volume of trash that authorities have to go through to capture the evidence is extremely challenging."

Kleeber says another challenge is that there are multiple locations to investigate since police say surveillance video shows that Fotis Dulos made multiple stops to throw out garbage bags in Hartford.

Kleber can relate to the detectives on this case -- he helped solve the case of Christina Long, a teen who disappeared from Danbury 15 years ago. Long was murdered and her body recovered in Greenwich. In solving missing persons cases, Kleber says physical evidence is key.

"There's certainly a lot of circumstantial evidence and blood evidence and I'm sure other evidence we're not aware of," he says.

Kleber says law enforcement may not reveal everything they know because they want any eyewitnesses to share what they know firsthand.

"I don't want a witness to come tell law enforcement what they read in the paper, or seen on the news. They want their own story to be told, how they remember it," he explains.

Fotis Dulos is still in custody.