AUBURN — Two of three men charged in the robbery last year of a Lewiston man’s medical marijuana have admitted to related charges.

Ricardo Hairston, 19, of Lisbon Street, Lewiston, pleaded guilty Thursday to robbery, violation of condition of release and criminal threatening. He had been a track star at Edward Little High School where he graduated in 2010.

Hairston agreed to an underlying sentence of 10 years on the Class B robbery charge, the most serious of the charges, which was reduced from a Class A. The time he must serve on that charge was capped at five years, but he can argue for less time at sentencing, according to a plea agreement.

He also agreed to three years of probation, during which time he may not use or have alcohol, drugs, firearms or dangerous weapons and would be subject to random searches and testing. His sentencing is scheduled for May 3.

Kevin A. Stitchel, 22, of Bartlett Street pleaded guilty to charges of robbery and criminal threatening with a dangerous weapon. On the robbery charge, he was sentenced last week to 10 years in prison with all but four years suspended, plus three years of probation. He will serve a two-year concurrent sentence for the lesser charge.

Derrick J. McDuffy, 21, also of Bartlett Street, is awaiting a mental health exam and is expected to be appointed a new lawyer.

McDuffy was charged with robbery, burglary and criminal threatening, all felonies. He also was charged with violation of condition of release and theft by unauthorized taking, both misdemeanors.

The three were accused of robbing Scott and Wanda Breton at their Pierce Street apartment in September 2011.

Scott Breton said the men, whom he didn’t know, had come for his marijuana, which he said he used legally for health problems. One of the men put a shotgun against his face and threatened repeatedly to shoot him, Breton said.

One of the men was armed with a double-barreled shotgun, another with a handgun, when they kicked in his door at about 9 a.m., the Bretons told police.

The couple said the men were aware that Scott Breton had marijuana. The couple also was robbed of an iPod, a cellphone and a laptop computer.

Wanda Breton called police from her cellphone. Within minutes, police arrived.

Although Scott Breton didn’t recognize the men, he was able to describe them. Police tracked the three to an apartment building around the corner at 21 Walnut St. At that address, police found the two guns and some of the stolen property that had been stuffed into a dryer. They said they found the suspects hiding in another apartment on the third floor.

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