A Colorado dentist has been charged with killing his wife and the mother of his six children by spiking her protein shakes with arsenic and cyanide, so he could start a new life with his lover, according to court documents.

James Toliver Craig, 45, was arrested Sunday on one count of first-degree murder for allegedly fatally poisoning his wife, Angela Craig, who was pronounced brain-dead on March 18 and later taken off life support.

As his 43-year-old spouse lay dying in the hospital, Craig allegedly flew his orthodontist lover from Austin to Denver, with whom he had exchanged “sexually explicit emails,” according to a detailed arrest affidavit.

The charging document described the couple’s troubled marriage, financial difficulties and Craig’s alleged sinister plot to murder her.

“In totality, this investigation has proven that James has gone to great lengths to try and end his wife’s life,” Aurora Police Detective Bobbi Olson wrote in the affidavit.

On Feb. 27, Craig created a secret email account, jimandwaffles.com, which he only used on a computer in his now-shuttered Summerbrook Dental Office, investigators allege.

“While using this account, he researched multiple ‘undetectable poisons.” His Google history also revealed searches for “how many grams of pure arsenic will kill a human?” and “Is Arsenic Detectible in Autopsy?”,