Gina Floria claimed her 1-year-old grandson, Cain, ingested the drug on Dec. 19, WEYI reported.
"My son got a text from a friend of his saying that my grandson had got ahold of some meth," Floria alleged to the station.
Cain was transported to an area hospital and put on life support, but he died 10 days later, on Dec. 29.
According to FOX 2, Floria claimed Coombs physically abused the boy after giving him the drug.
Coombs and Jones-Bronner were each charged with assault with intent to murder, first-degree child abuse, torture, and delivering substances to a minor.
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On Feb. 27, a judge granted a request to upgrade the assault charge and now both Coombs and Jones-Bronner are facing first-degree murder charges.
The defendants are being held without bond and are scheduled to be back in court on April 17.
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