Police have arrested one of two men they say shot a postal worker in March, attempting to rob him during his morning route through the Mexican War Streets on the North Side.

Terry Shields, 18, was arrested yesterday at a North Side home by the Western Pennsylvania Fugitive Task Force after police efforts to "reach out to get him to turn himself in" failed, Pittsburgh police Sgt. Lavonnie Bickerstaff said.

Mr. Shields was charged with robbery and criminal conspiracy in the shooting of the 49-year-old letter carrier, who, police said, was emptying a green relay box at North Taylor Avenue and Palo Alto Street when two men approached and demanded money. One of the men fired four or five shots at the carrier as he ran down the street with his mailbag, striking the carrier in the right hand. The pair sought money, not mail, and got neither.

The second assailant, described by witnesses as 16 to 19 years old, remains at large.

"We have some leads, but we don't have any concrete suspects," said Sgt. Bickerstaff, of the robbery squad. "The investigation is ongoing."

Because the robbery victim is a postal employee, the U.S. Postal Inspection Service also is investigating.

Police were questioning Mr. Shields yesterday afternoon before he was lodged in the Allegheny County Jail.

Because Mr. Shields was arrested on a city warrant, his case will be prosecuted in state court. Other cases involving postal workers have been prosecuted under federal law, which carries tougher penalties.