The woman convicted of intentionally poisoning her son is set to tell her story on the news program "48 Hours."

Lacey Spears is serving 20 years to life after being found guilty of fatally poisoning her 5-year-old son Garnett by placing lethal amounts of salt in his feeding tube. Spears, who was living in Pound Ridge at the time of her son's death, maintains she did not kill him.

The Westchester District Attorney's Office tried the case. One theory prosecutors brought up was that Spears suffered from a rare disorder that causes a parent to fabricate or exaggerate a child's illness. Spears maintains she doesn't suffer from any illness and blames the staff at Westchester Medical Center.

Spears' appearance on "48 Hours" will air this weekend.