PORTLAND — A federal judge sentenced a Lewiston man on Monday to eight years in prison for distributing crack cocaine three years after he was convicted of selling fentanyl.

James Robertson, 30, had pleaded guilty last month to the Class C felony of distribution of cocaine base, a crime punishable by up to 20 years in prison.

Robertson had been free on supervised release from a 2017 conviction for distribution of fentanyl when he was arrested in February last year for selling crack.

U.S. District Court Judge George Z. Singal had sentenced Robertson in 2017 to 30 months in prison on the fentanyl distribution conviction.

Robertson’s attorney, Amy Fairfield, wrote in a sentencing memorandum that the latest conviction has resulted in “the horrible loss of James’ ability to be present for his girlfriend of several years . . . and her family and for his mother, . . . who James has recently reconnected with after being estranged from her for a over a decade as well as James’ long-awaited and much anticipation recognition of his terrible choices.”

Fairfield wrote that “James has made far too many mistakes. He owned his mistakes by pleading guilty knowing he will be sentenced to a prison term. He is very angry with himself for his behavior that led him here. He disappointed (his girlfriend) and her family. He has profound regret beyond a term of incarceration.”

She said her client had been seeking a 3-year sentence.

Investigators said that in January 2019, a confidential informant texted Robertson at the direction of agents to buy crack from Robertson at an address in Lewiston. Robertson used the same cell phone number he had given to probation officers.

The confidential informant wore a recording device and completed the drug transaction, according to an affidavit in court files.

In addition to the prison term, Judge Singal recommended Robertson enroll in a 500-hour comprehensive drug treatment program while in prison.