A woman was arrested after telling authorities she killed her two young children, according to Pennsylvania police and news reports.

Officers went to a Harmony Township home Saturday, Dec. 2, for a report of a 4-month-old child not breathing, WPXI reported, citing a criminal complaint. The child was pronounced dead at the scene.

The baby’s mother, 27-year-old Quanesha Lindsey, was interviewed by police and admitted to killing the child according to the complaint obtained by WTAE. She is accused of using a mannequin to show how she suffocated the baby to death..

While making the admission, Lindsey also said she killed her 2-year-old son in October, police told KDKA. She said she strangled the 2-year-old, according to police.

Text messages sent in October show Lindsey acknowledged the child’s death, but police were not notified until a relative called them, police said, according to WPXI and WTAE.

Lindsey was charged with murder, strangulation and abuse of a corpse, court records show. She was placed in the Beaver County Jail and denied bail.

A motive for the killings is unclear.

Harmony Township is about 25 miles northwest of Pittsburgh.