SANTA FE, N.M.—Authorities say a 76-year-old man is in custody for allegedly threatening a Santa Fe Prep student with a gun.

A 17-year-old student told police he was driving to school erratically about 8 a.m. Tuesday when a man followed him to campus while yelling obscenities at him.

The teen says the man demanded his driver's license and registration once they were stopped on school grounds.

When the boy refused to hand the items over, he says Allan Wheeler allegedly pulled out a small handgun and pointed it at the teen's stomach and again demanded the documents.

A school maintenance worker intervened and police were called.

Police say Wheeler is being held on suspicion of aggravated assault with a deadly weapon, child abuse and unlawfully carrying a firearm on school grounds.