Dentist Accused of Poisoning Wife's Protein Shakes Allegedly Wanted to Start 'New Life' with Orthodontist

A person close to mom of six Angela Craig told police the couple had been experiencing marital problems for years

Authorities say the Colorado dentist suspected of poisoning his wife's protein shakes was "working on starting a new life" with the Texas-based orthodontist police say was his mistress.

James Toliver Craig is accused of first-degree murder in connection with the death of his wife Angela Craig, according to the Aurora Police Department.

Craig, 45, was arrested Sunday.

According to the arrest affidavit, Craig is suspected of slipping potassium cyanide and arsenic into Angela's pre-workout shake beginning the morning of March 6. That day, she allegedly complained of feeling faint and dizzy, and Craig took her to the hospital afterward.

Angela, 43, was released that same day but was subsequently in and out of the hospital until she was last admitted March 15, the day she died, the affidavit reads.

An investigation into Angela's death revealed Craig had allegedly researched "undetectable poisons" and recently purchased potassium cyanide and arsenic.

Police say the symptoms Angela was experiencing up until the day she died, including loss of consciousness and seizures, were consistent with ingesting both substances.

James Craig and Angela Craig. Facebook

Furthermore, police say Craig had also been communicating with a fellow dental professional in Austin, Texas, via email in "what appears to be a sexually intimate relationship."

"It appears James was flying this woman into Denver while his wife and the mother of his children was dying in the hospital," according to the affidavit.

Police say additional email evidence suggested Craig told his alleged lover that Angela died, to which the woman allegedly responded, in part: "I do want to give you any comfort I can, but I do not feel it is right to mix in with all of those gathering to mourn Angela either and I do not want to meet your family as a friend and try to conceal what I feel for you."

"I love you," she allegedly wrote.

Want to keep up with the latest crime coverage? Sign up for PEOPLE's free True Crime newsletter for breaking crime news, ongoing trial coverage and details of intriguing unsolved cases.

A person close to Angela told police the couple had been experiencing marital problems for years and that Craig allegedly had a history of cheating and an addiction to pornography.

He also allegedly poisoned Angela in the past, according to the affidavit.

It's unclear if Craig has retained an attorney to comment on his behalf or entered a plea to the charge.

He is scheduled to appear in court Thursday.

If you are experiencing domestic violence, call the National Domestic Violence Hotline at 1-800-799-7233, or go to thehotline.org. All calls are toll-free and confidential. The hotline is available 24/7 in more than 170 languages.