The evening of September 15, 2014, began normally for the quiet community of Pickering, Ontario. No one ever imagined that it would soon take a dark turn when 39-year-old Carmela Knight was killed in her home. Known for her vibrant personality and close relationship with those around her, her life was cut short under circumstances that raised questions about some of her closest people. NBC’s ‘Dateline: Fire & Ice’ revisits the investigation that consisted of undercover operations. Additionally, it features interviews with the detectives who worked on the case and Carmela’s loved ones.
Carmela Knight’s Remains Were Identified Using Her Dental Records
Carmela Knight was welcomed into the world by her father and mother, Franca Agosta, sometime around 1975. She grew up in a loving household and loved playing with her beloved sister, Nancy Burridge. Carmela was described as the kindest person with a heart of gold. After completing her education, she began her professional journey as a Mortgage Agent at Mortgage Intelligence in Ontario. Sometime in her 20s, Carmela met David Knight at a nightclub. It didn’t take them long to start dating, and they soon tied the knot around 2000. Shortly after, Carmela and David welcomed their first son into their lives. Just three years later, they gave birth to their younger son, Dylan. Carmela was often called the “hockey mom” because she usually took her sons to hockey lessons and cheered them on from the sidelines.

The family ultimately settled into their home at 1164 Pebblestone Crescent in Pickering, Ontario. Unfortunately, Carmela’s beautiful life turned upside down on September 15, 2014. Around 7:50 pm, her neighbor called the authorities to report a fire in Carmela’s garage. Although her neighbor tried to call Carmela, she didn’t pick up. While the firefighters attempted to put out the fire, the rest of the officials learned that David and their two sons were at hockey practice. After the blaze was extinguished, detectives reportedly found the charred remains of an individual in the garage. They discovered a tourniquet and needle on the person’s arms, and the drug paraphernalia was found at the location, initially indicating a case of drug overdose.
The medical examiner later identified the person as Carmela through her dental records. According to records, the autopsy report revealed that her remains had signs of trauma, which could not be attributed to just the fire. It reportedly suggested that she had passed away before the fire started. The autopsy further uncovered that she had facial injuries and a neck compression due to strangulation. Ultimately, Carmela’s cause of death was determined to be blunt force trauma and neck compression, while the manner of death was ruled a homicide. The toxicology report revealed that she had no drugs in her system, indicating that there was an attempt to stage the scene as an overdose and an accidental fire.
New Details and Evidence Led the Officials to Someone Close to Carmela
When officials questioned David on September 15, 2014, he reportedly told them he left the house around 3:30 pm, went to McDonald’s, and then took his sons to the ice rink, where they practiced from 6:30 pm to 8 pm. According to investigative reports, he informed the detectives that he and Carmela slept in separate bedrooms and were in the process of an amicable separation. Reports state that they soon discovered from her home security system that the interior door sensors had been activated before Carmela arrived home from work at 5 pm, indicating that someone was in the house after David left. Investigators also learned from Franca that a few days before the murder, a man with a black SUV had approached Carmela in the backyard and asked about David, which had allegedly left Carmela unsettled.

According to official reports, the detectives discovered that the man was David’s ex-business partner, who alleged that David had stolen money from him. Shortly after, Carmela’s sister-in-law, Heather Knight, contacted the authorities and reportedly informed them that David’s brother, Matthew Knight, AKA Matt, had abruptly left Canada for Florida. In her statements, Heather claimed that he had allegedly told her that he could’ve stopped it. As per court records, Matt rushed out after hearing about the fire on September 15, but instead of going to David’s house, he went to meet a friend, Graham MacDonald. When Matt was contacted, he reportedly alleged that Heather was a liar and that he wouldn’t return to Canada.
Authorities then learned that Graham was also a friend of David. As per police reports, during his questioning, Graham claimed he had gone to visit his grandmother. In his statements, he further claimed that, since she was not at home, he took the GO train from Toronto to Pickering, before walking to a motel. However, no CCTV footage could confirm his alibi, unlike David’s. Yet, detectives learned during that interview that he had met David on September 15. According to reports, during his second interview, Graham claimed that he didn’t remember much of that day since he was on drugs. Records state that investigators learned from Franca that the separation of David and Carmela was turning ugly since she had filed for custody of her two sons, and the hearing was set just three days after her murder.
An Undercover Operation Helped Obtain a Confession From One of the Killers
During the investigation, authorities reportedly discovered that David also had a house in Florida. Court records indicate that around one and a half years before the murder, Carmela had found that David was having an affair with a woman, Jill Hartman, who was living in the Florida home. According to Nancy, David had promised to stop seeing Jill, and Carmela even took him to marriage counseling sessions. Reports state that, unfortunately, Carmela found out he was still unfaithful and decided to file for divorce. When officials questioned Jill, she reportedly informed them that David claimed to have been divorced for 6 years and was planning to start a life in Florida with Jill, his dog, and his sons. As per official reports, David attempted to flee to Florida, but authorities seized his passport because he had obtained it with false documents.

Officials also learned that David had taken life insurance policies on Carmela and would receive a payout of about $800,000 after her death, as per reports. According to court records, the detectives set up an undercover operation in which an undercover officer, Uncle Dan, convinced Graham that he could let a person who was dying of cancer (actually an undercover official) take the blame for Graham. Reports state that Graham ultimately confessed to the officials that he had ambushed Carmela at her home on September 15, before killing her, staging the scene, and setting the garage on fire. He reportedly admitted that the accelerant was gas that David brought in a gas can, which was confirmed through surveillance footage. During the confession, Graham revealed that David had offered him $100,000 for the murder.
According to police records, Uncle Dan convinced Graham to meet David at the bar and ask for the money, following which David paid him around $7,000. Ultimately, Graham and David were arrested on February 27, 2015, and charged with first-degree murder, conspiracy to commit murder, and arson. The arrest warrant for Matt was issued in March 2015, and he was later found in Florida before being brought back to Canada. He was arrested and charged with conspiracy to commit murder and accessory after the fact to murder. In 2017, he pleaded guilty to the accessory charge and received a one-year prison term. The trial of Graham began in January 2018, and he was found guilty of all charges. He was sentenced to life in prison, with the possibility of parole after 25 years. The trial of David began in October 2018, and he was convicted of his charges in February 2019. He was sentenced to life imprisonment with the eligibility for parole after 25 years in April 2019.
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