An Alexandria federal court jury yesterday found 29-year-old Alonso Eugene Glascoe of Washington guilty of assaulting an undercover D.C. police narcotics investigator during an April 9 incident at National Airport.

Glascoe, who was shot in the back during the incident, was charged with dragging Officer Roger Isaac Jr., who was caught in the window of Glascoe's car, through an airport parking lot after Isaac attempted to question him. Isaac was assigned to the U.S. Drug Enforcement Administration.

Officials said Glascoe had got off the Eastern Air Lines shuttle from New York and was driving his car from an airport parking lot when Isaac stopped him and showed identification.

Glascoe allegedly pinned the officer's arm in his automobile window and was attempting to drive off when the officer drew his revolver with his free hand and shot him. Glascoe's wound required surgery. Before the car came to a halt, it collided with five unoccupied cars parked in the lot. Isaac was treated for a knee injury.

On Tuesday, U.S. District Judge Oren R. Lewis granted a motion for judgment of acquittal on the first count of the two-count indictment. That count had charged Glascoe with possession of heroin with intent to distribute.

Sentencing was set for October.