ST. PETERSBURG, FL – A 17-year-old girl returned home from school on Tuesday afternoon to a devastating shock: her 4-year-old brother lifeless in their mother’s arms, the house stained with blood, according to local authorities.

Police identified the mother as Diana Elizabeth Cullom, 43, and charged her with first-degree murder in the death of her youngest son, Finley Cullom. Investigators allege that Cullom suffocated the boy with a plastic bag inside their residence on Tanglewood Drive NE.

Authorities responded to the scene shortly after 3:30 p.m. after receiving reports of an injured person and quickly discovered the boy dead in a bedroom. Cullom was also found inside the home, suffering from what officers described as self-inflicted stab wounds. Paramedics transported her to a local hospital for treatment, though her injuries were determined to be non-life-threatening. She was later released from the hospital and booked into the Pinellas County Jail.

Police initially believed the boy’s death was caused by stabbing due to the extensive blood found throughout the home. However, further investigation led detectives to conclude that the actual cause was suffocation with a plastic bag. The department confirmed the discovery of a note apparently written by Cullom, but officials have not revealed its contents.

Law enforcement officials stated that Cullom provided a formal statement after she was informed of her rights, though the specifics of what she said remain sealed as part of the ongoing investigation. To date, police have not disclosed a motive for the killing.

At the time of the incident, Cullom’s husband, a practicing dentist in St. Petersburg, was not present in the house. According to biographical information, Cullom had played a key role in supporting her husband’s dental practice, Crescent Lake Family Dentistry, and was the mother of four children.

Friends and family had described Cullom as a woman devoted to her loved ones and interested in a diverse set of activities, including outdoor adventures, travel, community service, and music. Her family is reportedly struggling to process the tragic loss and circumstances surrounding the case.

Neighbors expressed disbelief and sorrow, describing the Cullom household as a typically quiet, friendly presence in the neighborhood. The investigation is ongoing as officials work to understand the events leading up to the child’s death.

Police continue to appeal for anyone with information relevant to the case to come forward. No further details regarding legal proceedings or potential additional charges have been released at this time.