More details have emerged over how the internal affairs investigation of Waltham Police Chief Thomas LaCroix will be conducted.

LaCroix remains under house arrest and on paid leave from the Police Department as his Feb. 13 trial date approaches. He is accused of assaulting his wife and her friend at his Maynard home in June 2012.

An independent consultant will be hired to conduct an investigation of LaCroix’s actions and the results could lead to disciplinary actions, Acting Police Chief Keith MacPherson told Waltham Patch.

Normally, MacPherson said, an Internal Affairs Unit Officer of a rank higher than the officer being investigated conducts the investigation. Currently, however, every IA officer is of a lower rank than the chief.

The internal affairs investigation is a completely separate case that would only impact his employment status with the department, MacPherson said. LaCroix would still face different penalties pending the outcome of the criminal case. Mayor Jeanette McCarthy would make the final decision on any disciplinary actions, MacPherson said. McCarthy could not be reached for comment.

The internal affairs investigation could include testimony from the criminal trial, witness interviews and documents MacPherson said.

"If other things came to our attention... we may have to follow up that as well," MacPherson said.

It’s not clear when the internal investigation will begin, MacPherson said. McCarthy’s request for $20,000 for it is currently under review by the City Council’s Finance Committee.

If a trial never happens, MacPherson said, Internal Affairs officers would try to obtain the same information they would have received from the court hearings.