A Rayne woman engaged to marry the father of a 3-year-old boy whose May death was ruled a homicide was arrested Wednesday in the toddler’s killing.

Acadia Parish deputies booked Brittany Marie Prejean, 24, of the 800 block of Southeastern Avenue, on a count of first-degree murder in the death of Keaghyn Parsons, of Lake Arthur. Prejean’s arrest followed an eight-month, multiagency investigation into the case, said Maxine Trahan, a Sheriff’s Office spokeswoman.

Investigators determined Parsons was fatally injured while visiting his father, who left the child in Prejean’s care May 19 while he went to work, Trahan said.

Parsons was pronounced dead that day in Jennings after deputies responded to a call about an unresponsive child in the 2500 block of Riverside Road.

The Calcasieu Parish Coroner’s Office ruled Parsons’ death a homicide in June. His autopsy revealed a perforation in his small intestine was caused by blunt force to the stomach, Trahan said.

Prejean is being held at the Acadia Parish jail without bond.