A Pennsylvania woman accused of researching dangerous household items for months has been arrested in the death and alleged poisoning of her boyfriend’s 1-year-old.

The girl, who died in June, had ingested batteries, a metal screw and water beads, the state’s top prosecutor announced Thursday.

Aleisia Owens, 20, has been charged with criminal homicide, attempted homicide, aggravated assault of a child and endangering the welfare of a child, Pennsylvania Attorney General Michelle A. Henry said in a statement.

“The details of this case are heartbreaking,” the AG said. “It is hard to fathom someone taking deliberate steps to harm a completely helpless child, then mislead investigators about what happened. The investigation shows that, for months, the defendant conducted meticulous research on how certain substances harm children.”

It was not immediately clear Friday afternoon if Owens had an attorney.

The girl, Iris Alfera, died June 29, four days after she was hospitalized, the AG said.

An autopsy showed her cause of death was acetone poisoning, which caused organ failure. “Medical experts who examined the baby’s body concluded that the child was exposed to acetone just before her hospitalization,” Henry said.

The 1-year-old’s death was ruled a homicide by the medical examiner.

Before the baby’s death, the child ingested about 20 “water beads,” along with button-shaped batteries and a metal screw, officials said.

In the months leading up to the girl’s death, Owens searched the internet on her cellphone for information about household products that can cause harm or death to a child, the attorney general said.

Her searches included “beauty products that are poisonous to kids” and “medications leading to cause accidental poisoning deaths in children,” the statement said.

New Castle Police Chief Robert Salem said in the statement, officers worked “tirelessly” on the case, along with prosecutors in the attorney general’s office, to make an arrest.

“I am extremely proud of the officers, detectives, and agents who were involved in investigating this complex case and arresting the person who was responsible for the child’s death,” Salem said.

Owens has been denied bail because of the homicide charges, Henry said. The Lawrence County District Attorney’s Office referred the case to the attorney general’s office for prosecution, Henry said.