Anne Castagna, who stands accused of poisoning her grandmother-in-law in Deptford, was denied a bail reduction Wednesday and remains jailed on a first-degree murder charge.

The Appellate Division of New Jersey Superior Court ruled that Castagna, 43, of Brooklawn, must pay $250,000 in bail to be released from custody. Castagna previously won a bail reduction from $350,000; her legal team sought a further reduction to $150,000.

Castagna allegedly killed her husband’s grandmother, Mary Groatman, by poisoning the 88-year-old woman at the Deptford Center for Rehabilitation and Healthcare. Groatman was a patient at the care center after a fall.

Prosecutors say Castagna researched the effects of antifreeze on the body, and allegedly slipped Groatman ethylene glycol—the toxic chemical that is the primary ingredient in antifreeze—on Aug. 19, 2012. The elderly woman became unconscious and alert Underwood-Memorial Hospital staff suspected poisoning. Groatman died at the Woodbury hospital on Aug. 24.

“If it wasn’t for the exhaustive and important work by the emergency room, this lady might’ve gotten away with murder,” Gloucester County Prosecutor Sean Dalton said at the time. “(Groatman) was in good health for someone 88 years of age,” he said.