PORTLAND, Maine — A Cushing man was sentenced Thursday in federal court to 43 months in prison for robbing a Rockland pharmacy at knifepoint last year.

Elbert Ranquist Jr. was sentenced in U.S. District Court in Portland by Judge Nancy Torresen. He also will be on supervised release for three years upon his release.

He could have faced up to 20 years in prison for the single charge of interference with commerce by robbery.

Ranquist has been held in jail since his arrest on the evening of Aug. 5, 2013, for the robbery of Jensen Pharmacy.

The state originally charged Ranquist with robbery but acknowledged in court hearings the FBI was investigating the case on behalf of the U.S. Attorney’s Office. Ranquist was indicted Nov. 20 by a federal grand jury.

An affidavit filed by police in Rockland District Court in August stated Curtis Jensen, owner of Jensen’s Pharmacy, reported he had been robbed by Ranquist. Jensen said he recognized Ranquist because the suspect had been in the pharmacy two times earlier in the day to pick up prescriptions.

According to the affidavit, Ranquist went to the counter, pulled out a knife with a 4- to 5-inch blade and demanded oxycodone pills.

Ranquist was on probation for an arson conviction when arrested in connection with the pharmacy robbery.

The robbery at Jensen Pharmacy was the second that occurred within about a year at that business. In August 2013, Michael Willis, 29, was sentenced to seven years in jail with all but 21 months suspended for robbing the same pharmacy. He also was placed on probation for three years. That robbery occurred July 31, 2012.