In handling a case involving a missing laptop with sensitive financial data, the most important initial action regarding digital evidence is:

Securing the Scene:

Prevent Contamination: Secure the location where the laptop was last seen to prevent any further tampering or contamination of potential evidence.

Preservation: Ensure that any physical evidence related to the incident is preserved for further investigation.

Subsequent Steps:

Investigation: After securing the scene, proceed with interviewing personnel, reporting the incident to law enforcement, and analyzing the laptop (if found) without turning it on to avoid altering any evidence.

References:

Guidelines for handling digital evidence:NIST Digital Evidence

Best practices in digital forensics: SANS Institute