Trial may provide answers in Baby Gabriel search

Little Gabriel Johnson was 8-months-old when he was last spotted alive in 2009 at a Texas motel.

His mother, Elizabeth Johnson, allegedly told the father she killed the infant and put his body in a Dumpster. She later told police she drove from her home in Arizona to Texas and gave him to a couple she met in a San Antonio park.

Johnson is in a Phoenix jail cell awaiting trial for kidnapping, custodial interference and child abuse, and Gabriel's disappearance is still a mystery.

Some answers may surface Tuesday, when opening statements are expected in the trial of another woman, Tammi Smith.

Smith is accused of helping Johnson try to wrangle custody of the boy from his father, in order to adopt the little boy herself.

She is charged with forgery and conspiracy to commit custodial interference. She has pleaded not guilty and could face a sentence of six years if she's convicted.

Smith and Johnson allegedly met in June 2009, when both women were waiting for the same flight at the Indianapolis airport.

In statements to police, Smith described the 23-year-old Johnson as looking "scared" and "depressed."

Smith says she suggested to Johnson that she and her husband should adopt Gabriel.

Smith did not hear from Johnson until that December, when Johnson called to ask if the Smiths were still interested in the adoption.

Johnson was entangled in a custody dispute with Gabriel's father, Logan McQueary.

In court documents, prosecutors allege that Smith and her husband pressured McQueary into surrendering custody so they could adopt Gabriel, and that Smith falsely wrote the name of her cousin on a paternity document as Gabriel's possible father.

On December 17, 2009, a judge awarded Johnson and McQueary joint custody of Gabriel, but Johnson allegedly defied the ruling and set out for Texas with her son.

McQueary didn't hear from Johnson until several days later, when she reportedly sent him a text message saying she'd killed Gabriel.

She was arrested on December 30, 2009, in Miami Beach, Florida.

She told police that she'd given the boy to a unknown couple she met up with in San Antonio. She later told police she did this under Smith's direction.

Smith has maintained she does not know where the little boy is, and that she had nothing to do with the couple who supposedly received Gabriel. Smith's defense attorneys are hoping to introduce testimony from a psychologist who examined their client to show that Smith makes poor decisions in stressful situations and is naive and too trusting.