A mother in Florida who claimed her 2-year-old son was kidnapped has admitted to hitting the boy, causing him to have seizures, before leaving him to die in the woods, authorities said.

Charisse Stinson, 21, admitted during questioning by police in Largo that she hit her son, Jordan Belliveau, in the face “during a moment of frustration” after he sustained an unexplained injury to his right leg, according to an arrest affidavit obtained by the Tampa Bay Times.

Stinson then struck Jordan in the face with the back of her hand, sending his head into a wall in her home and causing him to have seizures. The boy’s condition worsened on Sunday, prompting Stinson to take the boy to a wooded area in the middle of the night and leave him there, according to the affidavit.

Stinson was arrested late Tuesday and is now being held without bail at the Pinellas County Jail on a first-degree murder charge. She’s expected to have her initial court appearance sometime Wednesday, the Tampa Bay Times reports.

Investigators had spent more than 60 hours searching for the boy in nearby wooded areas, as well as ponds and trash receptacles near Stinson’s apartment. She initially told police that a man named “Antwan” offered her and her son a ride late Saturday.

While in the car, Stinson told investigators, the man had struck her in the face, knocking her unconscious. When she awoke in Largo Central Park, her son was missing, she told police, leading investigators to issue an Amber Alert and release gas station surveillance video of a possible witness and a sketch of a suspect with gold teeth and dreadlocks.

Stinson reported her son missing early Sunday. His body was found late Tuesday afternoon behind a baseball field at the Largo Sports Complex, the Tampa Bay Times reports.

“This was a sad end to Jordan’s life,” Largo police said on Facebook.