AUBURN – Attorneys for a teenager accused of fatally stabbing a Lewiston man are hoping a judge will let them share the victim’s criminal history with a jury.

Androscoggin County Superior Court Justice Joyce Wheeler said Tuesday that she would decide later this week whether prior “bad acts” of Richard Lessard would be allowed into evidence during the trial. That trial is expected to start next week and last for roughly a week.

Sergio Hairston, 19, of Lewiston was indicted on charges of murder and aggravated assault in connection with an incident about a year ago that left Lessard dead and his wife, Pauline, wounded at an apartment at 186 Bartlett St. in Lewiston.

Attorney Heather Walker said at a pretrial court hearing that she and co-counsel Scott Quigley plan to show Hairston acted in self-defense in February 2006 when the Lessards tried to rob him, but she said she needs to inform jurors about Richard and Pauline Lessard’s prior actions that help support their client’s defense.

Assistant Attorney General Lisa Marchese said the only reason “bad acts” should be allowed is if Hairston knew about them before the stabbing.

In a separate ruling, Justice Wheeler said she would allow defense attorneys to refer to prior felony convictions and those related to the truthfulness of witnesses called by state prosecutors in an effort to diminish their credibility.

Wheeler also said the defense attorneys could gain access to medical records of a leg injury Lessard suffered in 2006. Lessard was shot in the leg in 2006 by an Auburn man in the driveway of the man’s Auburn home. Lessard had shown up at the man’s house unexpectedly and the two argued, police said. Pauline Lessard was at the man’s home at the time of the shooting, police said. The shooter was never charged in connection to the incident.

Walker said she wanted to be able to show jurors that Lessard was not incapacitated by the earlier injury at the time of the stabbing and that he provoked the shooter.

Assistant Attorney General Marchese said she had no plans to argue that Lessard was incapacitated.

Police said an unpaid drug debt by Lessard’s son may have triggered the stabbing.