PHOENIX -- Baby Gabriel Johnson has been missing for six weeks, despite investigations by two major police departments and the FBI, and some are questioning why an Amber Alert was never issued.

Gabriel was with his mother, Elizabeth Johnson, in San Antonio, Texas, when he disappeared. Johnson was later arrested in Florida and now sits in a Maricopa County jail on charges of kidnapping and child abuse.

When Gabriel's biological father, Logan McQueary, learned Johnson had taken the boy to Texas, he called police in both Tempe and San Antonio.

"We were told that (Johnson) was passing through … San Antonio," said San Antonio Police Chief William McManus. "Then we got the information, 10 days later, that she had stayed at the (Homestead) Hotel. So, as far as the Amber Alert goes … you know, there was not (an) opportunity for that."

Nevertheless, the fact that Johnson was "passing through" Texas has nothing to do with the state's Amber Alert criteria.

A few weeks after Gabriel disappeared, Texas authorities issued an Amber Alert for 8-year-old Aja Johnson and her alleged abductor, Lester Hobbs. Police said Hobbs snatched Aja in Oklahoma, and was feared to be passing through Texas.

Hobbs was wanted in connection with a homicide. The fact that Johnson was not believed to be an immediate threat to Gabriel was listed by Texas Department of Public Safety as a reason not to issue the alert.

Nevertheless, the request's denial came the day after Elizabeth sent a text message saying she would tell McQueary the location of "dead Gabriel's little blue body" once she was out of the country.

McQueary passed the information on to police, yet on Dec. 28, the Texas Department of Public Safety declined to issue an Amber Alert.

The same day she sent the text message, Johnson boarded a bus for Miami, without Gabriel.