The boy, identified as Kendall Anderson, is charged with murder, possession of an instrument of crime, and abuse of corpse.
This all began when he reported his mother missing on Saturday.
The woman, identified as 37-year-old Rashida Anderson, was found dead around 10:10 a.m. Monday behind her home on Jackson Street in South Philadelphia.
Police say Kendall bludgeoned his mother in the head with a hammer - killing her.
Investigators say the teen also used part of a chair to fatally beat his mother before dragging her body into an alley and covering her with trash.
Investigators believe this all took place on Friday, but Kendall waited until Saturday to report her missing.
While police were questioning him again on Monday, they say he broke down and admitted that he killed his mother.
Neighbors say they never saw much of either Rashida or Kendall.
One woman who worked with her briefly as a Census taker says she never shared much of her personal life and rarely talked about her family.
Rashida Anderson was one of three sisters. Doreen Anderson said her sister was a kind person and devout Jehovah's Witness who spent much of her spare time involved in church activities.
She says there were never any signs of trouble between Rashida and Kendall, until this past weekend's sudden eruption of deadly violence.
Action News has also learned that Kendall Anderson had trouble at school and for the past two years he was attending Camelot at Boone which is a disciplinary high school.