Kouri Richins, the Utah mother and children's book author convicted of killing her husband with a poisoned cocktail, had some chilling advice for their three children before being sentenced to life in prison without the possibility of parole.

In a Utah courtroom, Kouri stood up and told the three sons, had with her husband she has been convicted of killing ... "Be like your dad."

During the sentencing hearing, the boys' paternal grandfather told the judge Kouri deserved a life sentence without parole so his grandsons would "never have to live with the fear that the person responsible for taking their father could ever harm them again."

Kouri was convicted of aggravated murder in her husband's March 2022 death ... for lacing his drink with five times the lethal dose of fentanyl.

A Utah jury also found her guilty of attempted aggravated murder for trying to kill her husband on Valentine's Day 2022 with a fentanyl-laced sandwich ... plus insurance fraud and forgery related to his life insurance policy.

Prosecutors said she was planning to leave her husband for another man when she killed him.

Good thing she didn't tell her kids to be like her.