Himelright also had been charged with attempted first- and second-degree murder, first- and second-degree assault, felony theft, kidnapping and reckless endangerment.
Those charges were dropped Thursday in exchange for the plea, according to Assistant Washington County State's Attorney Mark Wolfe, who handled the prosecution.
Police in Washington County began working with authorities in North Carolina last June 2, trying to learn more about Philip James Bean's claim he was abducted from Hagerstown on May 31 and left for dead nearly 450 miles away.
Bean, 23, was treated for injuries in Asheville, N.C., and released the next day, according to Buncombe County sheriff's deputies.
Bean had been found near the town of Arden, N.C., bound with an elastic cord, a shirt over his head and bleeding from his neck, according to Buncombe County Sheriff Bobby Medford.
Bean told deputies in North Carolina that he gave a ride to two women in Hagerstown on May 31, knowing only that one of them was named Michelle or Zoe.
As Bean and the two women drove around Hagerstown, they picked up two men. The five were riding in Bean's red Camaro in the Smithsburg area when the passengers asked him to drive them to Florida.
When Bean refused, his throat was slit with his own knife.
Bean testified Thursday he was put into the hatchback/trunk of his own car and driven for several hours into the mountains of North Carolina near the French Broad River.
"He ordered me out of the car and beat me on the back and shoulders," Bean said. "I was rolled over several times until I fell about three feet into water."
Bean said he laid there until he heard the car drive away.
"I got my feet free and went to the road," Bean said. "A car stopped and a woman helped me."
Bean left the witness stand and showed the six men and six women on the jury the lengthy scar on his neck.
Himelright's co-defendant, a Hagerstown teenager who pleaded guilty Dec. 16 to conspiracy to commit first-degree assault, also testified Thursday.
Sentencing was delayed so Zoe Elizabeth Currin, of 12022 Heather Drive, could testify.
In exchange for her cooperation, charges of attempted first- and second-degree murder, armed carjacking, kidnapping, theft and conspiracy to commit kidnapping, armed carjacking and first- and second-degree murder were dropped.