CONCORD — An accomplice in the robberies of a Kay Jewelers in Tilton and a Northeast Credit Union bank in Manchester last year was sentenced to three years in federal prison Monday after pleading guilty in May.

Shyloe Piper Johnson, 25, of Sanbornton, was sentenced in U.S. District Court after pleading guilty to aiding and abetting the robberies.

Johnson admitted to being the get-away driver for the Tilton robbery in December 2011, and to providing surveillance and other assistance for the robbery of the credit union, which took place in November.

Johnson was arrested in Laconia in December with her then boyfriend, Walter Williams of Compton, Calif., the alleged ringleader in the robberies, as well as the robbery of the Hannoush Jewelers on South Willow Street in Manchester in October 2011.

Williams has pleaded guilty to the robberies and is scheduled to be sentenced Nov. 26.

Delano Nelson, also of Compton, was indicted by a federal grand jury in August in connection with both of the jewelry store robberies and is scheduled for trial in November.

Several others have been charged in state court with lesser offenses related to the crimes.

Johnson pleaded guilty in May. In addition to the prison sentence, she was ordered to a three-year period of supervision by U.S. Probation.

The case was investigated by the Federal Bureau of Investigation and Manchester and Tilton police.

The plea was announced Monday by U.S. Attorney for New Hampshire John Kacavas.