(DETROIT) - A woman accused of killing her 9 year old son and burying his body in her Detroit backyard has been charged with murder.

A shallow grave holding remains was discovered on January 6 while the landlord was preparing the house for new tenants. No details were released at that time although Detroit police acknowledged an investigation was underway.

Zemar King was smothered to death on October 24, two weeks before his 41 year old mother left for Georgia with a 3 year old son, according to Wayne County Prosecutor Kym Worthy.

Worthy says she has been a prosecutor for a long time and often says she has seen it all, but the horrors of this child abuse case defy that.

Worthy says the alleged actions of this defendant are among the most callous she has seen and hope to never see again.

The mother was arrested January 10 in an unrelated case in Cobb County, Georgia, according to online records. She was awaiting extradition to Michigan on a murder charge and other crimes.

Worthy said Zemar's father recently became aware of the boy's death.