Investigators say a plastic bag was used; a knife and note were recovered at the home.
ST. PETERSBURG, Fla. — A 43-year-old St. Petersburg mother is charged with first-degree murder after police say she suffocated her 4-year-old son Tuesday afternoon at a home on Tanglewood Drive NE. She appeared in court Wednesday and was ordered held without bond.
Authorities identified the mother as Diana Elizabeth Cullom. Police say her teenage daughter returned from school around 3:30 p.m. Tuesday and found Cullom in a bedroom holding her son, identified by family records as Finley. Responding officers located a knife and a note at the scene and took Cullom to a hospital for treatment of self-inflicted but non-life-threatening stab wounds. The medical examiner ruled the boy died by suffocation. The case moved quickly from an emergency response to a homicide investigation, with detectives and crime-scene technicians processing the home into the evening and early morning hours.
Police Chief Anthony Holloway said the 16-year-old daughter called 911 and met officers outside the residence. “With the note and the way the scene is right now, the mom appears to be the suspect,” Holloway said, adding that the investigation remains active and that detectives are reviewing timelines and electronic records. Investigators said initial information suggested stabbing, but an autopsy found no stab wounds on the child and concluded that a plastic bag had been used. Officers noted blood on the bed and in other areas of the house consistent with the mother’s injuries. Police also said there had been no prior calls for service to the address.
At a first-appearance hearing Wednesday, a judge ordered Cullom jailed without bond and barred her from contacting her daughter, who is considered a key witness. A defense attorney standing with Cullom said he had no comment after the hearing. The child’s father, a local dentist, was not home at the time and arrived as officers were processing the scene, according to police. Investigators did not describe the contents of the note recovered at the house. They also did not discuss any potential mental health history, saying only that detectives will review medical records and conduct additional interviews before releasing further details.
The home sits in the 1700 block of Tanglewood Drive NE in a quiet, waterfront neighborhood. Neighbors told reporters the family kept to themselves and that they had not seen police at the house before. The police chief acknowledged the emotional toll on first responders and the teen who discovered the scene, noting that victim services were offered to the daughter and to officers. The medical examiner’s finding shifted the focus of the case from an apparent stabbing to a suffocation death, a change officials underscored to correct early reports and avoid confusion as court records begin to move through the system.
Detectives are seeking a detailed timeline of Tuesday’s events, including when the daughter left for school and when the mother was injured. Additional lab testing and analysis of the note are pending. Police said formal charging documents will be filed by prosecutors in coming days. A more detailed arrest affidavit is expected to outline the evidence recovered from the bedroom, electronic devices, and any witness statements. Officials said they plan to release further updates after the State Attorney’s Office reviews the case.
Outside the courthouse Wednesday afternoon, several family members wept quietly as Cullom stood in jail garb with bandaged arms. In the neighborhood, residents set small stuffed animals near the driveway and lowered shades as crime-scene vans left. “Everybody’s heart is heavy,” Holloway said, adding that his department’s family services unit would continue working with the teenager. As of Wednesday evening, investigators had not announced a motive. The contents of the note remained undisclosed.
As of late Wednesday, Cullom remained in the Pinellas County Jail with no bond. Police said the investigation is continuing this week, with additional statements expected after prosecutors file charges and a written order is docketed. A subsequent court hearing is expected in the coming days.
Author note: Last updated January 30, 2026.