An American dentist who poisoned his wife's protein shakes repeatedly before administering a fatal dose of cyanide while she was in hospital has been jailed for life.
James Craig, 45, had searched on the internet "how to make murder look like a heart attack" weeks before killing his wife of 23 years, a trial heard.
The Colorado resident had also searched "is arsenic detectable in an autopsy?" on a computer at his dental practice in the Denver suburb of Aurora, the jury was told.
Prosecutors argued the dentist had poisoned Angela Craig, the mother of his six children, over the course of 10 days in the month that she died.
The dentist later administered a final dose of cyanide when she was hospitalised after earlier attempts failed.
The hospital pinioning had baffled doctors who were confused over her symptoms.
She was initially sent to hospital after Craig put potassium cyanide administered in her protein shake.
Toxicology tests revealed Mrs Craig died of poisoning from cyanide and tetrahydrozoline, an ingredient typically found in over-the-counter eye drops, the coroner said.
Text messages within an affidavit revealed that Mrs Craig documented feeling odd after the alleged drugging – asking her husband whether he had tried to poison her again.
He was conducting an affair with an orthodontist at the time when the alleged murder took place.
The protein shake was made by James and given to Angela on March 6 – precipitating a ten-day deterioration of her health before she lost brain function on March 15.
Text messages contained within the affidavit showed that Angela documented feeling odd after the alleged drugging – asking her husband whether he had tried to poison her again.
Craig allegedly flew his mistress he was having an affair with into Colorado while Angela was suffering the effects of the poison in hospital.
District Judge Shay Whitaker issued Craig a life sentence without the possibility of parole for a first-degree murder – the mandatory conviction for this offence in the state of Colorado.
The jury rejected his claim that he had helped his wife kill herself after he said he wanted a divorce after cheating on her.
Deputy District Attorney Michael Mauro said Craig clearly wanted out of his marriage but caved to "greed and cowardice" by committing murder.
"The jury said it loudly: Angela was not suicidal. She had no knowledge of or participation in what happened to her," he said.
Craig was also found guilty of trying to cover up the murder by asking others to fake evidence and testimony that would make it look as though his wife had taken her own life or wanted to frame him for her death.
He was also found guilty of asking one of his daughters to create a fake video of her mother requesting to be poisoned.
Craig was also convicted trying to get a fellow inmate to murder the main detective investigating his wife's death.
He was acquitted of one manslaughter charge.
