In the summer of 2019, Denise Hallowell, a former teacher, was found brutally murdered with an ax at her lakefront Florida home. Her adoptive son, Carlos Hallowell, was the only other person present in the house at the time of the crime. But the teen maintained his innocence, as there was nothing linking him to the crime at first.
Later, detectives made a crucial discovery at the bottom of the lake: Denise's phone and three CCTV cameras, which were removed from the house. Digital data was then used to incriminate Carlos, who partially admitted to the slaying but claimed that he blacked out and only woke up to find the weapon embedded in the victim's head. He was eventually found guilty of murder.
Denise Hallowell's killing is set to be featured on NBC Dateline's upcoming episode titled Horror at the Lake on Friday, August 18, 2023. The all-new episode airs on the channel at 9 pm ET.
Here's an official synopsis that discloses more about the upcoming case:
"Terror sweeps through a quiet Florida community when a local teacher is murdered with an axe in her lakefront home. Dennis Murphy reports."
Denise Hallowell's ax murder: A gruesome crime scene, a solo suspect, and digital evidence, among other details from the case
1) The murder weapon was embedded in Denise's head
In the evening hours of July 13, 2019, Denise Hallowell's adoptive son, 17-year-old Carlos, found her dead at their lakefront Florida home and called 911. When first responders arrived at the crime scene, they found the former school teacher in her bedroom with the ax still embedded in the back of her head. Carlos claimed he had been napping and was awakened by the barking dogs, only to find her dead. However, there were no signs of a break-in at the house.
2) Police learned about abuse allegations against Denise Hallowell
Denise had previously made headlines in September 2015 when she was arrested and accused of physically abusing her younger adoptive son, who was only 12 years old at the time, as per a Fox 13 report. The allegations stated that she locked the boy in a room and starved him.
However, Denise was released due to a lack of evidence to back these claims. Moreover, her second son, Carlos, then 14 years old, had defended her and corroborated her claims that the younger son had a troubled past. But after the accusations surfaced, she lost her job and reputation in the community.
3) Digital evidence was found at the bottom of the lake
While investigating Denise Hallowell's murder, detectives had their sights set on Carlos but required evidence to make a move against him. The breakthrough was made when they found the 57-year-old victim's iPhone and three CCTV cameras, which had been removed from the house, at the bottom of the lake neighboring their house.
The evidence found on these devices was contradictory to Carlos' claims that he had been napping when his adoptive mother was murdered. Detectives then used phone GPS and timetables of device activities to outline the teen's movements from that evening until the time he made the distressing 911 call.
4) Carlos Hallowell confessed to arguing with Denise that afternoon
According to the Citrus County Chronicle, on September 16 of that same year, Carlos was brought in for questioning concerning Denise Hallowell's murder a second time. He maintained his innocence throughout despite being confronted with the newly unearthed digital evidence before admitting to throwing the devices in the lake because he "panicked."
The teen then changed his story and confessed to having a history of bickering with Denise, accusing the latter of being verbally abusive. The two reportedly argued that afternoon over his schooling. He claimed that his adoptive mother was about to stop paying for his schooling because he wished to pursue technical college instead of a four-year degree, according to her wishes.
5) Talking about the attack on Denise Hallowell, Carlos claimed he had no memory of it
Further confessing about the events that transpired that day, Carlos Hallowell claimed that he took the ax out of the shed to sharpen it in the garage and that he only intended to chop wood. But the next thing he remembered was walking up to Denise's room and staying at the doorway. The teen claimed he blacked out after that and only woke up to find his adoptive mother with an ex embedded in her head.
Carlos was reportedly charged with premeditated murder and pleaded not guilty. Two years later, he was convicted of the charge and handed a life sentence with a sentencing review after 25 years.
An all-new episode of NBC Dateline airs every Friday at 9 pm ET.