FALL RIVER, MASS. >> The Department of Youth Services is conducting an internal review to figure out how an 18-year-old with a history of mental illness and a lengthy criminal record was able to flee a staff secure group home in Fall River, only to resurface as a suspect in a killing weeks later.

The Boston Globe reports <URL destination="http://bit.ly/1R7826c%20">an agency spokeswoman confirmed last week that Alexander Mills escaped the unlocked facility on Nov. 10.

</URL>Officials say although DYS immediately notified local police of Mills' departure, state police weren't made aware that he was missing for two weeks.

Mills, now charged in the killing of a New Bedford cab driver, was supposed to remain under DYS supervision until he turned 21 years old.

Mills' attorney said his client has "significant mental health issues."