The New Orleans Police Department (NOPD) may employ a number of methods, including:
Finding fresh information or leads by going over case files, evidence, and witness statements from the first investigation.
The process of re-interviewing suspects, victims, and witnesses to glean new information and spot discrepancies in their stories.
Making use of computers and forensics databases to track down leads and identify suspects. DNA testing, fingerprint comparison, and other forensic methods could be used.
Using incentives, collaborating with the media, and social media to solicit participation and collect data from the public.
Sharing knowledge and resources with other law enforcement organizations including the FBI and local prosecutors.
Having seasoned investigators look into cold cases on a regular basis in the hopes of finding fresh leads.
Making use of the expertise of dedicated teams like the cold case squad, which is made up of investigators with specialized experience and education in solving cold cases.
It's crucial to keep in mind that the specifics of each cold case may necessitate a different approach from law enforcement. It's possible that the New Orleans, Louisiana Police Department has its own method for dealing with cold cases.