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?”, Fox News reported.

Finally, he purchased crystalline metalloid arsenic from Amazon, which was delivered on March 4 to the family’s $1.3 home while his wife returned from a trip to Utah the next day

On March 6, the couple worked out together and her husband made her a “pre-workout shake in which James gave her extra protein because she was feeling sluggish,” the affidavit alleges.

Hours later, she complained of feeling faint and dizzy and was admitted to the hospital but discharged the same day.

“I feel drugged,” Angela Craig texted her husband. Her sister told police that James Craig had drugged his wife about five years earlier because he had planned to commit suicide and didn’t want her to stop him.

“Given our history, I know that must be a trigger,” he replied to his wife in a text. “Just for the record, I didn’t drug you. I am super worried though. You looked pale before I left. Like your lips even.”

That night, her husband allegedly ordered Oleandrin, another poison, which was intercepted before delivery.

The deranged dentist was soon back at his keyboard allegedly ordering more poison. On March 8, he allegedly purchased a rush delivery of potassium cyanide, which arrived at his dental office on March 13.

Meanwhile, his wife was readmitted to the hospital on March 9, where she remained for five days, aligning nicely with a two-day visit from his paramour.

On March 15, one day after Angela Craig was discharged from the hospital, she was readmitted and “started to suffer from a severe seizure,” the affidavit says. She was rushed to the intensive care unit and pronounced brain dead.

James Craig’s mistress returned to Denver the next day.

Her sister, Toni Kofoed, told investigators that the couple’s marriage had always been “tumultuous” and that James Craig had “multiple affairs with several women” and was “addicted to pornography since he was a teenager.”

Angela Craig told her sister several times over the past 16 years that she planned to leave him, but he always convinced her to stay. The couple was also broke and on the verge of declaring bankruptcy for a second time, the documents allege.

Angela Craig had complained to her sister that her husband had recently gambled away over $2,000 on a trip to Las Vegas.

Police launched an investigation after James Craig’s business partner, Ryan Redfearn, reported his suspicion that the dentist had poisoned his wife.

Redfearn confronted James Craig about the cyanide that was delivered to the dental office. He allegedly claimed that his wife asked him to order it, implying it was so she could commit suicide.

“At that point, Ryan told James to stop talking and get a lawyer,” the affidavit says.