A Colorado dentist was arrested early Sunday and charged with the poisoning death of his 43-year-old wife.

Aurora Police said James Toliver Craig, 45, drove his wife to the hospital on Wednesday evening when she complained of severe headaches and dizziness. Once there, investigators say, she deteriorated rapidly and was put on a ventilator in intensive care.

A short time later, she was declared medically brain dead, police said.

Meanwhile, police were investigating the details and determined the victim had been poisoned. They obtained an arrest warrant for Craig not long after his wife was taken off life support.

“When the suspicious details of this case came to light, our team of officers and homicide detectives tirelessly worked to uncover the truth behind the victim’s sudden illness and death,” said Division Chief Mark Hildebrand in a statement. “It was quickly discovered this was in fact a heinous, complex and calculated murder. I am very proud of our Major Crimes Homicide Unit’s hard work in solving this case and pursuing justice for the victim.”

Police did not release the victim’s identity, but according to his bio page at Summerbrook Dental Group, where he practices, his wife’s name was Angela, and they had six children.

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[Featured image: James Craig/Aurora Police Department]