A final suspect has pleaded guilty in the shooting deaths of two boys who police say were slain in a botched robbery.

Deandre Witherspoon, 24, pleaded guilty Monday to second-degree murder in the killings of Orlando Herron, 13, and Darren Johnson, 11. The two were found shot in the head inside their ransacked home in February.

Authorities have said the boys were the victims of a drug-related robbery of their older cousin, an admitted drug dealer who survived being shot at the home.

Witherspoon, the sixth and final suspect in the case, avoided a potential life sentence by agreeing to the plea. His trial was set to begin Tuesday.

He now faces 22 to 40 years when he is sentenced Nov. 12.

Separate juries earlier this month returned guilty verdicts against Sonya O'Neal, 38, and Robert Reed, 36. They face mandatory sentences of life in prison when they are sentenced Wednesday.

Prosecutors said Witherspoon hatched the plan to rob the boys' cousin of drugs and money, and O'Neal did the shooting. Three others have pleaded guilty.