Note: Authorities first said the boy's name was Johnson, but referred to him as Gonzalez Friday.

SCOTLAND COUNTY, N.C. -- A massive search continued in North Carolina Friday for a missing 4-year-old boy, the subject of an Amber Alert.

Authorities said there have been no major developments in the case of Raul Gonzalez. Efforts have been shifted from search and rescue to an investigation. The FBI and SBI are now involved.

The Scotland County Sheriff's Office said Johnson has black hair and brown eyes. He is about three feet tall and weighs a little under 40 pounds.

Raul Gonzalez / Photo: NC Department of Public Safety
Raul Gonzalez / Photo: NC Department of Public Safety

Officials said the boy's grandfather was watching him Wednesday when he lost track of the child and called police.

The child's mother was at work when she got the phone call that her son had disappeared.

"I just couldn't believe it when he called me. I wished I would have stayed home yesterday. Just hoping he’s still out there," said Annie Johnson.

Johnson was wearing a white and orange tiger-striped shirt with tiger graphics printed on it and a pair of white pants with rocket ships printed on them, authorities said.

The boy was last seen traveling on foot in Laurinburg by a neighbor, according to authorities.

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Raul Gonzalez / Photo: NC Department of Public Safety

On Wednesday night, crews searched a pond near the area Johnson was last spotted. Police dogs tracked the boy's scent, and authorities spotted barefoot footprints. The pond was drained on Friday, but there was no word whether anything was found.

A search also took place in a nearby wooded area. More than 300 law enforcement officers and volunteers joined in the effort, including a crew from the Charlotte Fire Department.

Authorities said so far there is no evidence of foul play. Anyone with information on Gonzalez is asked to call 911 or 910-276-3385.