What is a primary tool used by Cold Case Investigators to connect suspects with their relatives?

A primary tool used by Cold Case Investigators to connect suspects with their relatives is DNA evidence. This technique is particularly powerful because it allows investigators to analyze genetic material collected from crime scenes and compare it to DNA profiles of known individuals, including potential suspects and their relatives. Through the use of databases, such as those maintained by law enforcement agencies, investigators can identify familial connections even when the suspect's DNA is not in the system.

This method is crucial in cold cases where traditional evidence may be lacking or where witnesses cannot provide sufficient information. DNA analysis has the capacity to yield results that bridge gaps in a case that has remained unsolved for years, making it an invaluable tool in modern criminal investigations.

While fingerprint analysis, surveillance footage, and interviews with witnesses play important roles in different contexts, they may not offer the same depth of connection between suspects and relatives as DNA does, particularly when building a case based on familial relationships.