A month of fear and bewilderment has apparently ended for a black Adelphi family with the arrest of three High Point high school students. The students were arrested in connection with a cross-burning last Nov. 5 outside the family's home. Prince George's County fire officials said yesterday.

For Edna and Egbert Higgins, who moved with two of their four children into Adelphi last July, the arrests halted a series of annoying, sometimes frightening, and apparently senseless racially-oriented pranks that began early in October.

But fire officials found the Higgins problems were somewhat familiar. The cross-burning outside the Higgins home was the tenth such incident reported to authorities in Prince George's County this year, according to Fire Captain Duncan Munro.

"We're not overwhelmed by them," Munro said. "but they happen, all over the County - sometimes out of the clear blue, with no apparent motive."

Munro said the fire investigators have placed particular emphasis on stopping cross-burnings in the county, and in recent years have solved 60 percent of such reported cases. The percentage of other, similar cases solved is usually about 20 percent, Munro said.

The Higgins case was a fairly typical one. In early October, a large fire-cracker was wedged in the family's door, and then exploded, shattering a pane of glass and destroyig a door screen.

On Holloween night, the trees in the family's yard were covered with toilet paper. Then sometime during the early hours of Nov. 5, the trees were papered again, pumpkins were smashed on the house, "nigger" and "k'k'k" were scrawled on the family car with soap, and a three-foot cross was burned in the yard.