DAVISON TWP. (WWJ) – Beginning first thing Wednesday morning, state and federal law enforcement will begin a large-scale search for a missing 9-year-old boy.

An AMBER Alert was issued for Omarion Humphrey who has been missing since Saturday evening from a Fourth of July gathering at Lake Callis Recreation Complex in Genesee County’s Davison Township, near Flint.

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Davison Township police chief Rick Freeman told reporters Tuesday afternoon that they’re they are still “exhaustively” searching — although they did scale back efforts during the day — due in part to the wet weather, and because of the boy’s severe autism.

“This has been a risk from the beginning. Our search efforts could actually, because of his condition, be causing him to dig in further … if he is in fact where we’re searching,” Freeman said.

The chief said Wednesday’s “large-scale technical search” would involve professional search and rescue teams and uniformed officers from several law enforcement agencies — including the FBI which has been involved since Sunday.

Volunteers, meantime, are being asked to search main streets and in backyards and pools — anywhere where Omarion could be hiding. In addition, police say people who visited Callis Lake Park since Saturday should check and re-check their vehicles and campers for the boy.

Omarion Humphrey  was last seen at Callis Lake Park. (credit: Jon Hewett/WWJ)

Omarion Humphrey was last seen at Callis Lake Park. (credit: Jon Hewett/WWJ)

Police dive teams were searching the water at the park on Tuesday. Both Callis and neighboring Abernathy Park will be closed to the public Wednesday for the massive coordinated effort covering about a 5-mile radius.

David Skinner of Otisville was among the many volunteers pitching in on Tuesday.

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“Every life is meaningful, you know what I’m saying? Regardless of who old they is, what color they are, you know — it could be somebody’s grandchild, somebody’s child,” Skinner said. “The whole idea is we’re supposed to help one another.”

Dailene Schroder traveled from Clinton Township to help.

“It’s very tough because there’s a lot of wooded area, a lot of ravines, a lot of different areas that he could’ve gone — the railroad tracks…just a lot of different open area,” she said.

The boy  is about 4-feet tall and 70 pounds with black hair and brown eyes. He was last seen wearing only black shorts with a thin, red stripe — no shirt and no shoes.

Authorities say Omarion may not speak but answers to the name “Mars.”

As far as what happened to him, investigators say they’re still not ruling anything out.

Anyone who thinks they’ve seen Omarion should immediately call 911. Anyone with other information is urged to contact police at 810-732-4720.

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