BELLE CHASSE, La. - A U.S. woman has been arrested on a charge of first-degree murder after police say she injected alcohol-based hand sanitizer into the feeding tube of her 17-month-old son, who had Down syndrome.

Twenty-year-old Erika Wigstrom was being held without bond after her arrest Tuesday. Plaquemines Parish Sheriff's Commander Eric Becnel says she told police she wanted to end Lucas Ruiz's suffering. NOLA.com/The Times-Picayune reports that Wigstrom broke down in tears during a court appearance Wednesday.

Lucas died Jan. 24. Becnel says the child also had been poisoned with alcohol in October 2012 while hospitalized for treatment of a heart defect. Becnel says the child's father, Cesar Ruiz, confessed in that instance but that Wigstrom now has confessed to poisoning the child both times.