Carl Eric Brandt, also known as Charlie, was born on February 23, 1957, in Fort Wayne, Indiana. He was the second child of Herbert and Ilsa Brandt, who were German immigrants. The family originally settled in Texas before moving to Connecticut and then to Indiana. Herbert worked as a laborer and eventually became a draftsman and project engineer for International Harvester. Because of his father’s job, the family moved frequently, and Charlie and his older sister, Angela, attended several different schools throughout their childhood.

Charlie was considered a good student, but he was shy and struggled to adjust to new environments. In September 1968, the Brandt family relocated to Fort Wayne when Herbert was transferred to a plant there. The family often vacationed in Florida, where Charlie enjoyed hunting small game with his father.

On January 3, 1971, an incident marked a significant turning point in Charlie's life. He shot his parents in their home when he was just 13 years old. His mother, who was pregnant at the time, was killed, while his father survived. After this event, Charlie spent a year in a psychiatric hospital before being released back into the care of his family. Due to his age, he was not charged with any crime. Following his release, the family moved to Ormond Beach, Florida.

After moving to Florida, Charlie pursued a degree in electronics and became a radar specialist for Ford Aerospace in Astor. He married Theresa "Teri" Helfrich in 1986, and their wedding was a private affair with no family members in attendance. Charlie and Teri settled in a beach house on Big Pine Key in 1989.

On January 3, 1971, in Fort Wayne, Indiana, 13-year-old Charlie Brandt shot his parents. His mother, Ilsa, who was eight months pregnant, and his father, Herbert, were both home. Charlie used his father's handgun, which he had taken from a dresser. Ilsa was killed instantly, along with her unborn child. Herbert survived.

Charlie then went to his sister Angela's room with the intent to shoot her, but the gun malfunctioned. After a struggle, Angela managed to calm Charlie down. She convinced him to go upstairs to get blankets for their younger sisters, who were unharmed. Angela then fled the house and sought help from neighbors. Charlie followed her but then confessed to a neighbor, saying, "I just shot my mom and dad." His father later identified him as the attacker.

After the shooting, Charlie told Angela that he could not remember what happened. He seemed to be in a trance-like state. When interviewed by the police, Charlie mentioned that various issues at school led to a breaking point in his mind. He also referred to an incident shortly before the shooting, where his father had killed their dog while hunting.

Due to his age, Charlie could not be tried for murder. He spent a year in a psychiatric hospital and was released in June 1972. After his release, his family moved to Florida.

On September 13, 2004, Charlie and his wife, Theresa "Teri" Helfrich, were staying at his niece Michelle Lynn Jones' house to escape Hurricane Ivan. During their visit, Teri was found stabbed to death on the couch, and Michelle’s body was discovered dismembered with her heart removed. Charlie was not found initially. He had hanged himself in the garage.

Following the murders, police found evidence linking Charlie to other violent crimes. They discovered a 1989 murder of a woman near his home, Sherry Perisho. Her body was found floating, and she had been similarly mutilated. Investigators matched a composite sketch of a man seen near the murder scene to Charlie.

The investigation led to a closer look at twenty-six unsolved murders in Florida. They considered three specific cases of interest. The first was Carol Sullivan, a 12-year-old girl who disappeared in 1978. The second was Lisa Saunders, a 20-year-old woman found murdered in 1988. The third was Darlene Toler, a sex worker found in Miami in 1995.

Despite the investigations, substantial evidence to connect Charlie to the other cases was lacking, apart from the confirmed murder of Sherry Perisho. The true number of his victims remains unknown, but he is suspected in multiple unsolved cases.