Mayor Sue Hack won’t be prosecuted for violating the state’s conflict of interest laws, although the state attorney general’s office said today she technically violated portions of the act.

In a letter released this afternoon, Atty. Gen. Paul Morrison’s office said it was declining to prosecute Hack for a failure to properly file a document listing her ownership interest in Deciphera Pharmaceuticals, a company that city commissioners have agreed to give more than $1 million in economic development incentives.

Investigators with the Morrison’s office said Hack didn’t properly fill out a state-mandated Statement of Substantial Interest form showing that she owned more than $5,000 in stock in the Lawrence-based company. But assistant attorney general Barry Disney said the violation was technical in nature and would not be prosecuted. Disney wrote that because Hack had verbally disclosed her ownership interest in the company, she had mitigated the damage of mistakenly not filing the form. She also abstained from the vote to give Deciphera up to $125,000 a year for 10 years in city money.

But Hack did participate in a closed-door executive session where the Deciphera deal was discussed. Allegations had been made that Hack’s participation in that meeting constituted a violation of the state law prohibiting elected officials who have a substantial interest in a company from participating in the making of a contract with that company.

The attorney general’s office, however, said it didn’t have the necessary evidence to prosecute Hack on that issue. Disney wrote that “there is no evidence that Mayor Hack participated in this meeting in any way other than by her attendance.”

A spokeswoman with the attorney general’s office said city officials provided the attorney general’s office with a description of what took place in the closed door meeting, and that description indicated that Hack did not offer any opinions or participate in any discussion regarding the matter.

But Disney said Hack’s participation in the closed-door meeting was questionable.

“I do believe her attendance created an appearance of impropriety,” Disney wrote.

If Hack had been convicted of violating that portion of the state’s conflict of interest laws, she would have been required to resign her office.

The attorney general’s office is investigating whether the city’s closed-door meeting on Deciphera violated the state’s open meetings act. That investigation is ongoing.