BOSTON (WWLP) - A Stoughton man was sentenced to prison in connection to two armed robberies of letter carriers. According to charging documents, two suspects, Myesha Lewis of Boston and Kenneth Demosthene of Stoughton, allegedly attempted to steal an arrow key, which is used to open designated blue USPS collection boxes in specific areas. The USPS has seen an increase in these types of thefts recently. The keys are the property of USPS therefore it is a federal offense for anyone unauthorized to have one in their possession. Since July 2022, there have been at least 23 assaults on letter carriers in eastern Massachusetts. In 10 incidents, they successfully stole the key and in six of those incidents, a knife or firearm was used in the robbery. On November 29, 2022, Lewis and Demosthene allegedly followed and forcibly robbed a letter carrier in Mattapan of their arrow key. Demosthene allegedly approached the postal worker and said "I'm going to need your master key," before going into the carrier's satchel and taking the arrow key. The key was secured to the carrier's waist with a brass chain, which was broken by the suspects. They then left the area in a rental vehicle. On December 16, 2022, the two suspects allegedly followed another letter carrier and robbed them at Knifepoint in Hyde Park. Demosthene allegedly said to the postal worker, "Give me your f****** arrow key." The letter carrier put their hands in the air as the two suspects found and forcibly broke the brass chain where the key was stored on the letter carrier's body. They then left the area on foot. Lewis and Demosthene were later arrested and have been charged with: Two counts each of robbery of any person having lawful charge, control, or custody of any mail matter or of any money or other property of the United States, aiding and abetting Two counts each of assaulting, resisting, or impeding certain officers or employees, aiding and abetting Demosthene pleaded guilty and was sentenced on Wednesday to three years in prison, to be followed by three years of supervised release. Lewis is due back in court on October 30th. Local News Headlines Minor injuries reported in three-car collision in Springfield Sen. Warren urges action on gun trafficking in Springfield Massachusetts Senate suspends their rules Voting measures for incarcerated people WWLP-22News, an NBC affiliate, began broadcasting in March 1953 to provide local news, network, syndicated, and local programming to western Massachusetts. Watch the 22News Digital Edition weekdays at 4 p.m. on WWLP.com.