PORTLAND, Maine — The Maine Supreme Judicial Court on Thursday unanimously reversed the conviction of a Pittsfield man on one count each of aggravated assault and domestic violence terrorizing because of improper jury instructions.

Daniel C. Baker, 42, was tried by a jury in January 2014 at the Penobscot Judicial Center. District Court Judge Bruce Jordan presided over the trial and gave the jury instructions.

“The [judge] instructed the jury that it should find Baker guilty merely if the state proved the charge, without also requiring the jury to deliberate on the issue of self-defense, but also directed the jury to consider that issue,” Justice Jeffrey Hjelm wrote for the court in a 13-page decision. “[The judge’s] subsequent instructions on the issue were unclear and fell short of informing the jury of its duty to acquit Baker if it found that the state had not disproved Baker’s contention that he acted in self-defense.”

Baker was found guilty in connection with a November 2012 incident involving his former girlfriend. The jury found him not guilty of attempted gross sexual assault.

On April 1, 2014, Baker was sentenced to five years with all but two years suspended on the assault charge and a concurrent six months behind bars on the terrorizing charge. He is incarcerated at the Downeast Correctional Facility and was scheduled to be released in June.

Baker will be retried, Penobscot County Assistant District Attorney Tracy Collins, who prosecuted the case, said Thursday in an email.

The prosecutor and Baker also could reach a plea agreement where he would plead guilty to a lesser charge and be sentenced to time served.

A bail hearing could be held later this month to determine if Baker will be released while his case is pending.

Jamesa J. Drake, the Auburn attorney who handled Baker’s appeal, praised the decision Thursday.

“The Law Court has a deep respect for the role that jurors play in criminal trials and their decision today reflects that,” she said in an email. “The court reaffirmed that a criminal verdict isn’t any good if the jurors are not properly instructed. It’s pretty hard to argue with that idea.”