ATLANTA, Ga. (Atlanta News First) - Testimony in the sentencing hearing for the teenager behind the deadly 2024 Apalachee High School shooting is set to resume Tuesday morning. Colt Gray, now 16, pleaded guilty to all 55 charges in the shooting, which killed teachers Cristina Irimie and Ricky Aspinwall and 14-year-old students Mason Schermerhorn and Christian Angulo. The plea was non-negotiated, meaning the state and defense did not offer Colt a deal or agree to a sentence. Colt's charges included several counts of malice murder, aggravated assault, aggravated battery and first-degree cruelty to children. PREVIOUS COVERAGE: Teen pleads guilty to all 55 counts in deadly 2024 shooting at Apalachee High School On Monday, a forensic psychologist who evaluated Gray after the shooting at the request of an attorney for the teen testified that during their first meeting in May 2025, Gray asked if he could pull his arms inside his sweatshirt to wrap them around himself. Another focal point in Monday's hearing was Gray's online talk about school shootings and his alleged obsession with Nikolas Cruz, who was convicted in the 2018 shooting at Marjory Stoneman Douglas High School in Parkland, Florida. The court also looked at pages from a notebook in which Colt detailed his plans for the shooting step-by-step and heard an interview conducted with Colt about 30 minutes after the shooting. In the audio recording, Colt sobbed hysterically as he admitted to the shooting, detailing uncontrollable urges and voices telling him to do things. Colt previously pleaded not guilty and was slated for a trial in October. Colin Gray, Colt's father, was convicted of multiple charges - including second-degree murder, involuntary manslaughter, reckless conduct and second-degree child cruelty - in March after prosecutors said he gave Colin the gun used in the shooting despite knowledge of his son's poor mental health. He is set to face sentencing on Thursday. MORE COVERAGE: Accused Apalachee High School sho #atlantanewsfirst #crimewatchatlanta