A Wisconsin official says a Michigan man accused of fatally shooting three teens after ambushing them near the Wisconsin-Michigan border last summer is expected to drop his insanity plea.

A Marinette County judge has scheduled a hearing for Wednesday for Scott J. Johnson of Kingsford, Michigan.

Wisconsin Department of Justice spokesman William Cosh says Johnson is expected to withdraw his insanity plea to charges that include three counts of first-degree intentional homicide.

Attorneys for Johnson did not immediately return telephone messages Friday.

Prosecutors say the 38-year-old Johnson fired about 17 shots at a group of swimmers at the Menominee River on July 31, killing three Michigan teens. Johnson's trial is scheduled to start March 16.