A 17-year-old Columbia youth was arrested yesterday by Howard County police and charged with murder and robbery in the stabbing death of a High's store clerk Saturday at a busy shopping center in Columbia.

Police said they arrested David A. Hartless at his home in the 10000 block of Hyla Brook Road after customers at the store provided descriptions of the youth. The stabbing death was the first homicide in Columbia since 1984, according to police.

Hartless was charged as an adult in the slaying of Angelica Velazco, 20, also of Columbia, who was found by a customer in the back of the store with multiple stab wounds of the neck, arms and abdomen.

Police said Hartless was a former employe of another High's store nearby and had been casually acquainted with Velazco.

The incident occurred at about 1 p.m. at the Wilde Lake Village Center just off Twin Rivers Road. Police said the store's cash registers had been emptied but declined to say how much had been taken.

Hartless was being held in the Howard County jail last night pending a bond hearing scheduled in Howard County District Court today.

Police said they do not have evidence of a motive in the slaying beyond robbery. A police spokeswoman said that the suspect, after stabbing Velazco and dumping her in the back of the store, pretended to be a clerk and waited on several customers before fleeing. A few minutes later, Velazco's body was discovered by a customer, and police were called.

The store is one of several shops in a largely residential area of town houses and apartment buildings. The store has no windows on three sides, and its interior is not visible from the adjacent road and parking lot. Its entrance faces a covered walkway, which was reported to have been filled with shoppers and other pedestrians Saturday when the stabbing occurred.

High's officials and store employes declined to comment yesterday on the killing.