The Murder of Rosemary Johnson
| Full Name | Rosemary Mattesich Johnson |
| Age | 69 |
| Location | Cape Coral, Florida |
| Protection Order | Granted March 2025 |
| Case Type | Elder Abuse -- Family Violence |
Rosemary Johnson
Rosemary Mattesich Johnson was 69 years old and lived in Cape Coral, Florida. She had significant mobility issues and relied on a walker to get around. She had daughters who loved her and stayed in contact with her daily. Her daughter described her as sweet and loving and caring.
Rosemary had allowed her son Devin to live with her even as his behavior became increasingly violent and frightening. She tried to do right by him. She reported him to police twice. She pressed charges. She was granted a protection order. She told police in her own words that she was scared of him and had been staying at her daughters' homes to feel safe. Her daughter later told investigators that Rosemary had legitimate fears that her son would one day kill her.
Rosemary did everything the system asked of her. She reported the abuse. She got the protection order. She stayed at her daughters' homes. None of it was enough to protect her. She deserved better from the people and systems around her. We will say her name.
What We Know
Devin Bryant Johnson, 28, lived with his mother Rosemary Johnson, 69, at her home on Jacaranda Parkway West in Cape Coral, Florida. He had no income and was not able to work. He had a documented history of substance abuse including opioids and cocaine, and his family said he suffered from schizophrenia, though he did not consistently take his medication. Rosemary had recently taken out a home equity line of credit of approximately $100,000, and investigators later noted that Devin may have had access to her bank accounts.
In January 2025, Devin punched Rosemary in the head, threw her walker across the room, moved it further away each time she tried to reach it, smashed her phone on the floor, and then cut the power to the home, leaving her trapped in her power recliner. She eventually used a laundry basket to reach her walker and flagged down a neighbor for help. She pressed charges. Devin spent a month in jail. In March 2025, he grabbed her arms, held her down, bruised her wrists, and spat in her face because he wanted her phone. A Lee County circuit court judge granted Rosemary a protection order in late March 2025. She told police she was scared of her son and had been staying at her daughters' homes to feel safe.
On the morning of September 16, 2025, surveillance video captured Devin leaving the home and going to Publix where he bought bleach and paper towels. That afternoon at around 1:25 p.m. Rosemary's daughter arrived to check on her after she was not answering her phone. She entered through an unlocked side door, found blood on the living room floor, and discovered her mother in her recliner covered by a blanket. When she lifted the blanket she saw obvious injuries to her head and neck. She called 911. Police arrived within eight minutes and pronounced Rosemary dead at 1:34 p.m.
The medical examiner found upward of 100 stab wounds caused by both a plain-edged and serrated knife, both of which were found inside the home, one broken. Rosemary had deep lacerations to her face and neck, defensive wounds on her hands, and a broken hyoid bone consistent with mechanical asphyxiation. She had been strangled as well as stabbed.
How It Unfolded
The Investigation
Investigators quickly identified Devin as the primary and only suspect. Multiple witnesses in the neighborhood had seen him leaving the home in a blood-covered gray Toyota Corolla. The Cape Coral Police Department's forensics unit conducted an extensive evidence collection at the scene, finding bloody footprints and shoe prints throughout the living room, blood on the light switch and floors in Devin's bedroom and bathroom, bloodied clothing on the sink counter, an OxyContin bottle in Rosemary's name on Devin's dresser, and clear plastic bags with white residue consistent with cocaine along with cut straws.
The medical examiner found two types of knife wounds on Rosemary's body, consistent with both a plain-edged and a serrated blade. Both knives were recovered at the scene, one of which was broken. Rosemary also had a broken hyoid bone consistent with mechanical asphyxiation, meaning she was strangled as well as stabbed. She had defensive wounds on her hands, indicating she fought back.
Devin's phone, reviewed by investigators after his arrest in Collier County, showed he had searched for flights to Costa Rica in the hours following the murder. He had already purchased bleach and paper towels that morning from Publix.
A possible motive identified by investigators was financial. Rosemary had recently taken out a home equity line of credit of approximately $100,000. Devin had no income and may have had access to her bank accounts. On December 10, 2025, State Attorney Amira Fox convened the Lee County Grand Jury, which returned a capital felony indictment upgrading the charge to first-degree murder.
The Accused
She Is Not Forgotten
Rosemary Johnson was 69 years old, sweet and loving and caring, according to her family. She had daughters who called her every day. She had a cross placed at her front door after she died. She was someone whose absence left a real and permanent wound.
She also reported her son to police twice, pressed charges, obtained a protection order, and told police in writing that she was afraid he would one day kill her. She did everything she was supposed to do. A judge granted her the protection order. It did not protect her. This is the reality of elder abuse and domestic violence, a piece of paper cannot always stop a person determined to cause harm, and the systems designed to protect vulnerable people do not always have the tools or resources to follow through.
Rosemary's daughter Renee Caney found her mother's body that day. She told reporters she will never unsee what she saw. She has called publicly for mental health reform, saying her brother needed treatment, not just incarceration. That is her grief to carry and her voice to use. Rosemary deserved both justice and protection. We hope she gets both.
We will say her name. Rosemary Mattesich Johnson. She was sweet and loving and caring and she deserved to be safe in her own home.
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