Feb. 2, 2010 -- Investigators are "less and less optimistic" missing 8-month-old Gabriel Johnson is alive, despite the arrest and interrogation today of Tammi Smith, a person of interest in the baby's disappearance, police said.
Neither Smith nor the boy's biological mother, Elizabeth Johnson, have been helpful in providing information about where the baby might be, Tempe, Ariz., police Lt. Mike Horn said.
Smith was arrested this morning on charges of forgery, custodial interference, and conspiracy to commit custodial interference, Tempe police said.
Smith, 37, and her husband, Jack, said they were in talks to adopt Gabriel before he disappeared in December.
Smith was interviewed by police and gave a statement following her arrest, but the information wasn't likely to help the investigation, Horn said.
Investigators do not believe Smith knows where Gabriel is, but she is considered a flight risk, according to arresting documents. She was arrested for her alleged involvement in a wrongful adoption.
The Smiths were previously named as persons of interest in Gabriel's case. Police served a search warrant on their home, believing the two may be withholding information. Police took their phone records and laptop. Jack Smith is no longer a person of interest in the case, Horn said.
Smith's attorney, Michael Kimerer, said she has always been forthcoming in her meetings with the police.
"When Tammi went and visited the police she told them everything she knows," he said.
Gabriel's mother, Elizabeth Johnson, and the boy's biological father, Logan McQueary, were in the middle of a custody dispute when Johnson fled Arizona with Gabriel before Christmas. She allegedly sent text messages to McQueary, saying she had killed their son and left his body in a trash bin.
Tammi Smith has continued speaking to Johnson, 23, and recently met her in a Tempe jail. Johnson was arrested and faces charges including kidnapping, child abuse and custodial interference.
"I looked in her eyes, I can tell you that baby is alive," Smith said.
Johnson later changed her story and said she gave the baby to a couple she met at random in a San Antonio park. Police have not been able to confirm that that couple exists.
The investigation is believed to be shifting from Arizona to Texas, where Gabriel was last seen.
Gabriel's biological father has hired a private investigator to help find his son.
McQueary held a vigil last week in Scottsdale with his friends and family. He said he still holds out hope that his son, who has been missing for more than a month, will be found alive and returned home safely.
"I hope he comes back soon," McQueary said. "I want him back more than anything else."
Babysitter Says Gabriel Was 'Acting Scared'
Johnson hired Urias through a Craigslist ad to babysit Gabriel while she was dealing with the custody dispute.
"Elizabeth told me if anyone came knocking on the door, not to answer it," Urias told ABC News. Tempe, Ariz., police released photographs of Gabriel taken by Johnson in the same Texas hotel room in the hope it would help them find the missing baby.
Although Gabriel looks healthy and active in the pictures, lying on a bed with toys and a pacifier, investigators say they worry that Gabriel appears to be holding a medicine dropper in two of the photos.
"Elizabeth told me to give him a bottle in about an hour, and then her exact words were to 'give him more medicine if he started crying to shut him up,'" Urias said.
"Gabriel wasn't acting like a normal baby," she said. "He was acting scared, he didn't want to play. He acted like he was sad."
The photographs were found in Johnson's camera following her arrest Dec. 29 in Miami.
Urias also said she found a large knife next to the bed in the motel room.
"It looked like a butcher type of knife and, you know, I thought that was weird because why would she have it next to her bed? It's something that would belong in the kitchen," Urias said.
The photographs were date-stamped Dec. 26, the last day anyone saw Gabriel.
Mom Describes Mystery Couple Who Supposedly Have Her Baby
Johnson described the couple as white and in their 30s. The man was tall with short black hair, and the woman was 5 feet 3 inches tall, with long blond hair.
Johnson said the two looked trustworthy and brought their own car seat ,and that they said they could keep baby Gabriel without anyone noticing.
"Yes, I'm sure he's alive," Johnson said in a jailhouse interview.
Gabriel's grandfather, Frank McQueary, said that is all the more reason to be vigilant.
"That next door neighbor may be buying stuff for a baby, and they didn't have a baby before," he said. "Let somebody know."
Anyone with information about Gabriel Johnson is asked to call the Tempe Police Department at (480) 350-8311.
ABC News' Deborah Johnson and Lee Ferran contributed to this report.