Dr. James Craig's murder trial features testimony from a dental office manager who received a suspicious package containing potassium cyanide shortly before his wife's death.

A Colorado dentist accused of killing his wife of 23 years by poisoning her protein shakes begins trial with opening arguments this week.

James Craig is accused of fatally poisoning his wife of 23 years and trying to cover his tracks by asking his cellmate to kill the lead investigator. Here's what to know as his Colorado trial starts.