(CNN)A Detroit mother arrested last month after police discovered the bodies of two of her children inside a freezer was arraigned this week on murder and torture charges. Wayne County Prosecutor Kym Worthy charged Mitchelle Angela Blair on Wednesday with killing her then 13-year-old daughter, Stoni Ann Blair, and her then 9-year-old son, Stephen Gage Berry. According to Detroit Police Chief James Craig, the bodies were found wrapped in plastic inside the freezer by a bailiff performing a court ordered eviction on March 24. The Wayne County medical examiner has since determined that Stoni died from multiple blunt trauma injuries and Stephen from multiple blunt trauma and thermal injuries. Both were determined to be homicides, according to spokesman Ryan Bridges. According to CNN affiliate WDIV,  investigators believe Stephen was scalded with hot water, beaten and strangled in August 2012, while Stoni was killed in May 2013. A message left for Blair's court appointed attorney, who entered not guilty pleas on her behalf at her arraignment, wasn't immediately returned. In addition to the two counts of premeditated murder -- each of which carries a mandatory life sentence without the possibility of parole --  Blair, 35, has been charged with two counts of torture, four counts of felony child abuse and one count of committing child abuse in the presence of another child. She has two other children, a 17-year-old daughter and an 8-year-old son, both of whom are now in in protective custody, according to Worthy. Blair will be back in court June 19 for a court ordered competency hearing.
Murder and torture charges for Detroit mom after bodies found in her freezer . Prosecutors accuse Mitchelle Angela Blair of killing her 13-year-old daughter and 9-year-old son . Their bodies were discovered in her freezer as she was evicted from her home last month .