A 19-year-old Rockland man who was sentenced less than a year ago to nine months in jail for sexually assaulting two girls is going back to prison after admitting to another sexual assault.

Matthew N. Boegel was sentenced Thursday, Jan. 25, in Knox County Unified Court to serve 42 months for violating his probation by committing the new crimes.

Boegel pleaded guilty to aggravated furnishing of marijuana to a person younger than 18 years old and sexual abuse of a minor. He received a five-year suspended jail term and was placed on probation for an additional two years.

The sentence will hang over Boegel once he serves his 42 months for the probation violation that resulted from the new offenses that occurred Oct. 28.

He had been sentenced in February 2017 to five years in jail with all but nine months suspended for unlawful sexual contact with two girls — ages 12 and 13. Two counts of gross sexual assault were dismissed in that case, which occurred during the summer of 2016.

Terms of his probation prohibited him from unsupervised contact with children younger than 16 years, and also he could not commit additional crimes.