A Colorado dentist was sentenced on Wednesday to life in prison without parole after being convicted in the 2023 murder of his wife, to whom investigators said he served protein shakes laced with arsenic before giving her a fatal dose of cyanide while she was hospitalized.

The dentist, James Craig, 47, of Aurora, Colo., was found guilty on all six counts in the poisoning of his wife, Angela Craig, 43, which caused her to have a seizure, difficulty breathing and a host of other symptoms that had confounded her doctors, prosecutors said.

Dr. Craig denied that he had killed his wife — they had six children and were married for 23 years — and had suggested to investigators that she had been depressed and was suicidal.

But he quickly drew suspicion, not only from the police, but also from friends and co-workers around the time of his wife’s death in March 2023.

His internet browsing history in particular helped cement his conviction of first-degree murder.

Less than three weeks before his wife’s death, he searched in Google: “How many grams of pure arsenic will kill a human” and “Is Arsenic Detectable in Autopsy?" on a computer at the dental practice where he worked, the police said.

Miriam Meservy, the couple’s eldest daughter, delivered a victim impact statement moments before sheriffs deputies led her father away for the rest of his life.