Prosecutors say Staples was with Pinckney at his residence in September 2015 when she became aware that he had a winning scratch-off lottery ticket. She called her son, who arrived soon after and stabbed and bludgeoned Pinckney to death.
The mother and son later went to a nearby convenience store to cash the ticket.
McCracken will be sentenced March 13 to 20 years to life in prison. His mother will be sentenced the same day to eight years.
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