• Reviewing the official case file: PIs often begin their work after the initial police investigation, relying on documents like the criminal docket, witness statements, and autopsy reports to identify overlooked details or potential gaps.

• Revisiting the crime scene: An investigator may revisit the crime scene to familiarize themselves with the environment and look for new or missed clues that may not have been catalogued in the police's initial sweep.

• Conducting independent interviews: A PI can re-interview witnesses, associates, and persons of interest. Since PIs operate separately from law enforcement, these interviews may reveal new information that was not shared during the initial police questioning.

• Building a victimology profile: PIs gather background information on the victim, including their lifestyle, habits, finances, and relationships. This helps create a complete picture of the victim's life and can uncover hidden motives or unknown connections.

• Providing forensic analysis: Some private investigative firms work with forensic experts who can re-examine physical evidence, such as ballistics, toxicology reports, and trace evidence, using newer techniques or a different perspective.

• Digital forensics: PIs can legally collect digital evidence, including social media activity, emails, and online transactions, to piece together a timeline or motive. They cannot illegally hack accounts or intercept communications.

• Assisting defense attorneys: If a suspect has been charged, a defense attorney may hire a PI to perform an independent investigation. This can help uncover evidence of a wrongful conviction or find new witnesses.

• Providing courtroom testimony: A PI can testify in court as a factual witness regarding the evidence they have collected, provided it was obtained legally. 

For a murder investigation to be legitimate and the evidence admissible in court, a private investigator in South Africa must follow strict legal and ethical guidelines. 

• PSiRA registration: All private investigators in South Africa must be registered with the Private Security Industry Regulatory Authority (PSiRA).

• No impersonation: PIs are prohibited from impersonating law enforcement officers.

• Legal evidence: Any evidence collected must be obtained legally. Evidence acquired through illegal means, such as trespassing or unauthorized surveillance, is inadmissible in court and could lead to criminal charges.

• Respect privacy: PIs must adhere to privacy laws, such as the Protection of Personal Information (POPI) Act. They can perform surveillance in public areas but cannot illegally monitor or trespass on private property.

• Informed interviews: When interviewing suspects or witnesses, a PI must identify themselves as a private investigator and ensure the person is not being intimidated or placed under duress. Recording interviews requires the interviewee's consent.