Four more juveniles have been charged as adults in the fatal stabbing and robbery of an 18-year-old Maryland teen inside a Metro station.

The four teens, all 17, were arrested in connection with the murder of Olney resident Olijawon Griffin, who was attacked and stabbed in the chest inside the Woodley Park Metro station on Nov. 17 after he confronted a group of 10 to 12 teenagers, at least some of whom had robbed him at gunpoint earlier in the night, according to authorities.

All four face charges of armed robbery. Three of the teens allegedly robbed Griffin in an alley near an Adams Morgan gas station, according to Bill Miller, spokesman for the District U.S. Attorney's Office. The fourth teen allegedly robbed Griffin's cousin during a fight at the Metro station, he said.

Defense attorneys objected to the charges against the juveniles, but a D.C. Superior Court judge had already signed the booking orders with warrants for the arrests of the four teens.

"They are not juveniles in the eyes of the law at this point. They are adults," said Magistrate Judge Diana Harris Epps.

The four teens are due in court Tuesday afternoon for an arraignment.

Griffin had tried to buy marijuana from the group of teenagers that night in Adams Morgan, but instead the group beat him and robbed him at gunpoint of his jacket and cellphone, according to court records.

After reuniting with his friends, Griffin walked to the Woodley Park Metro station to head home. There he spotted the teens who stole his property and confronted them, according to court records.

The group of teenagers attacked Griffin and his friends, beating 18-year-old Isaac Chase while he lay on the station platform. When Griffin went to help Chase, he squared off with one of the teens while another, 17-year-old Chavez Myers, snuck up behind Griffin and stabbed him in the chest, according to authorities.

Myers, a District Heights resident, was charged on Nov. 19 as an adult with second-degree murder and assault with a deadly weapon.

The four other teens, who were between 15 and 16, were arraigned Monday afternoon in juvenile court. Each was charged with two counts of armed robbery, felony assault, conspiracy to commit armed robbery and assault with a dangerous weapon -- much more than they faced at a juvenile hearing a week ago.

One of the juveniles was also charged with possession of an unregistered firearm, and another was charged with carrying a dangerous weapon -- a knife.

All told, nine Maryland teens between 15 and 17 years old were arrested in connection with the stabbing.