A Florida mother has been arrested and charged in the stabbing death of her four-year-old son.

According to WFLA, authorities have said that they are investigating the stabbing death of the child, Joseph Artis. The incident happened around 6 p.m. on Friday evening when St. Petersburg Police patrolling the area were flagged down by a concerned neighbor. The arriving officers saw Tasha Trotter outside of her home holding the boy, who was suffering from multiple stab wounds on his upper body and neck.

Trotter was still reportedly clutching the kitchen knife when officers told her to put the child down while they administrated CPR.

Officers arrested the 40-year-old mother and the boy was transported to a nearby hospital where he died of his injuries a short time later.

Bay News 9 noted that the boy’s grandmother, Carolyn Trotter, has had custody of him for the past three years and that his the mother visits with him occasionally. Family members have said that Trotter suffers from an unspecified mental illness.

Trotter, who also has three other children, has been charged with first-degree murder.