Shawn Marquies Henderson, 18, of the 700 block of Clopper Road in Gaithersburg and Abdul Tejan Williams, 21, of the 12900 block of Poppyseed Court in Germantown pleaded guilty to two counts each of armed robbery and one count each of attempted robbery.

Henderson also pleaded guilty to carrying a weapon openly with intent to injure. He will be sentenced Sept. 12 in Montgomery County Circuit Court and could face up to 63 years in prison.

The charge is a result of Henderson admitting to using the knife in the robberies, said Cheryl McCally, assistant state's attorney.

Williams also pleaded guilty to one count of conspiracy to utter a false document. He will be sentenced Sept. 29 and faces up to 70 years in prison.

Williams pleaded guilty to the charge because he took part in trying to cash a forged check from one of the robbery victims, McCally said.

Henderson and Williams were originally charged with 16 criminal counts, including first-degree assault and robbery with a dangerous and deadly weapon, following their Dec. 10 arrest.

But most of the charges were dropped in exchange for the guilty pleas, McCally said.

The robberies and attempted robbery occurred on Dec. 8 and 9.

Montgomery County Police received reports of two separate people having a man come up behind them, put a knife to their throats, rob them and leave a two-inch slice on each of their necks.

In a third incident, an unidentified man tried to rob a Germantown woman and also left a cut on her neck.

None of the injuries were life threatening, according to police at the time.

Police were able to arrest Henderson and Williams after Levon Craddolph, 37, of the 700 block of Clopper Road was arrested Dec. 10 at a Gaithersburg branch of Chevy Chase Bank on Bureau Drive for allegedly uttering a false document.

A check Craddolph was attempting to cash belonged to one of the two people who had been robbed, McCally said.

Craddolph told police he was helping a neighbor, Henderson, to cash the check because he did not have identification, McCally said.

After his arrest, Craddolph was charged with uttering a false document, but the charge was dropped due to insufficient evidence, McCally said.

When police questioned Henderson and Williams at Henderson's home, they had in their possession items belonging to the people who were robbed, McCally said.

Police then attained a warrant to search Williams' car where police found a bloody knife and dark jackets similar to what victims said their assailants wore, McCally said.

Henderson was 17-years-old at the time of the robberies and his July 17 guilty plea. He is being held at Rica Juvenile Detention Facility, McCally said.

Williams is being held at the Montgomery County Detention Center.