Bijan Manuel Nassirdaftari, a recent graduate of Gonzaga College High School, was working at a bagel shop on Rockville Pike this summer and preparing to attend freshman orientation at the University of Maryland.

Montgomery County police say he also was planning to buy a pound of marijuana from an acquaintance known as Mike.

They say the drug deal turned fatal. Nassirdaftari, 17, was shot in the head in Bethesda on Sunday night, as three friends in a nearby car heard the gunshot. The killers stole $900 that he was going to use to pay for the pot, police say.

One suspect was charged yesterday, and two others are in custody in connection with Nassirdaftari's death -- the second killing of a Montgomery County teenager in less than six weeks in what police describe as a drug deal gone awry.

Michael J. Manaugh, 18, of Baileys Court in Silver Spring, was charged with first-degree murder and armed robbery. He is being held without bond. Manaugh's family and his attorney declined comment.

The other two suspects are Edward Ricardo Thomas, 20, and Ardele Julia Monkkonen, 18, of the 1700 block of Harvard Street NW. They are being held in the District pending a court appearance to determine when they will be transferred to Montgomery, where two warrants were issued charging them with first-degree murder and armed robbery.

According to charging documents, Nassirdaftari, of Bethesda, and three friends drove Sunday night to the 10400 block of Rockville Pike to buy the marijuana. He had $700 in borrowed cash, plus an unspecified amount of his own money to complete the transaction. Nassirdaftari got into a car driven by Manaugh, with Thomas and Monkkonen as fellow passengers, police say.

The three suspects, who had agreed to rob Nassirdaftari's purchase money and not sell him any drugs, took Nassirdaftari to the intersection of Alta Vista Terrace and Alta Vista Road in Bethesda, followed by the car carrying Nassirdaftari's friends, the charging documents say.

When the cars stopped, police say, Nassirdaftari went to his friends' car to get an additional $200, then returned to the suspects' car.

Nassirdaftari told his friends he trusted the suspects and asked the friends to stay a distance from the other car, charging documents say. But when Nassirdaftari returned to the suspects' car, they tried to rob him, investigators say.

After struggling with Thomas, Nassirdaftari broke away, but Thomas chased him, shot him in the head and took his money, detectives say.

Nassirdaftari's friends were waiting in their car nearby when they heard a gunshot. They found Nassirdaftari's body lying on the sidewalk.

Nassirdaftari's family declined to comment yesterday.

At Manhattan Bagel on Rockville Pike, co-workers mourned the death of the teen who had worked there since October.

"He didn't strike me as someone who would get involved in that mess," said Steve Clagett, a friend and co-worker.

Fellow employees and regular customers, many of whom live in Nassirdaftari's neighborhood, have been somber since learning of the killing.

"We're still walking in a daze," said Bill Brown, the store's manager. "A lot of guys were good friends with him."

Nassirdaftari had been a shop customer since he was a boy, coming in with his mother, Brown said. He was supposed to attend freshman orientation this week and arranged for Clagett, 17, to cover his days on the schedule while he was away. Clagett said he first heard of his friend's slaying Monday on the radio.

"I looked forward to working with him every day," Clagett said.

"He was just an all-around good kid," said Brown.

Nassirdaftari's death marks the second fatal shooting in less than six weeks of a recent high school graduate in an apparent drug-related incident. Last month, Ezekiel Oak Babendreier, 18, a graduate of Damascus High School, was fatally stabbed after what police say was a conversation about buying marijuana outside a Germantown birthday party. Two teenagers have been charged in his killing.

Michael Manaugh of Silver Spring is charged in the Sunday shooting.