A mother’s decision to preserve a suspicious knife helped police secure crucial evidence in a murder case that has now resulted in her 28-year-old son being sentenced to 15 years in prison.
Tristan Cook was convicted of murder after pleading guilty to killing a man whose body was later discovered inside a garage in Extension 4, Eldorado Park.
The case dates back to 18, May, 2025, when Cook had an argument with his mother, Bianca Murray, at Goodwood Road.
According to Eldorado Park SAPS media liaison officer Sergeant Fezeka Khobo, Cook told his mother during the argument that he was not feeling well because he had just killed someone.
Murray initially did not believe him and suspected that he may have been under the influence of drugs.
Cook subsequently went to sleep in the garage where he lived. Police said he remained in the garage alongside the deceased from 18 May until 21 May.
On the morning of 21 May, at about 10am, a community member alerted Murray that there was a body inside the garage.
Murray was reportedly too afraid to investigate alone and asked the community member to accompany her. The garage was opened and the body was found inside.
A warden was contacted and assisted by alerting the police. However, while waiting for officers to arrive, Murray remembered an item she had discovered several days earlier.
According to Khobo, Murray had found a sharp black knife with some rust on it on May 18, the same day Cook allegedly told her he had killed someone.
Fearing that Cook could use the knife against her, Murray took possession of it and handed it to the warden, who kept it as evidence until police arrived.
Police secured the crime scene, arrested Cook and seized the knife as an exhibit. Cook has since pleaded guilty to murder and was sentenced to 15 years’ imprisonment.
The case highlights how information from community members and the preservation of potential evidence can assist investigators in building a criminal case.
