Mary Han was found dead of carbon monoxide poisoning, and Albuquerque police ruled the death a suicide.

Her estate recently filed a petition with the state’s high court.

Her family members argue that police violated state constitutional protections for the 53-year-old Han as a crime victim when the department investigated her death.

According to Albuquerque TV station KQRE, Han’s estate says the city police department had a conflict of interest in investigating her death and should have requested an outside law enforcement agency handle it.

Last August, a First Judicial District judge affirmed a decision changing Han’s manner of death on her autopsy report from suicide to undetermined.