A Colorado dentist accused of fatally poisoning his wife in a «complex and calculated murder» was arrested over the weekend, authorities announced.

James Toliver Craig, 45, a dentist in Aurora, was arrested Sunday, four days after he took his 43-year-old wife to a local hospital Wednesday night because she was complaining of «bad headaches and dizziness». Aurora Police Department saying.

After arriving at the hospital, the wife’s condition «deteriorated rapidly.» She was placed on a ventilator in the ICU and she «was medically declared brain dead a short time later,» authorities said.

An investigation into her suspicious death was launched and it was determined that she was poisoned. It is not clear what she was poisoned with.

A first-degree murder warrant was obtained early Sunday morning, shortly after doctors made the decision to disconnect the wife from life support.

Craig was booked into jail at 2 a.m. Sunday on a first-degree murder charge. It is not immediately clear if he has an attorney.

«When the suspicious details of this case came to light, our team of homicide officers and detectives worked tirelessly to uncover the truth behind the victim’s sudden illness and death,» said Investigations Division Chief Mark Hildebrand. .

“It was quickly discovered that this was a heinous, complex and calculated murder. I am very proud of the hard work of our Major Crimes Homicide Unit in solving this case and seeking justice for the victim,” he added.