Tsutomu Shimomura Helped Track Kevin Mitnick Across the United States

On Christmas Day 1994, someone broke into computer-security researcher Tsutomu Shimomura’s systems and copied files. The intrusion triggered one of the best-known pursuits in early internet history.

The researcher who became an investigator

Shimomura was a computational physicist and senior fellow at the San Diego Supercomputer Center. His work included computer and cellular security.

Evidence led him to believe Kevin Mitnick was connected to the intrusion. Shimomura worked with service providers and federal investigators to trace network activity and cellular signals.

Kevin Mitnick and Tsutomu Shimomura, central figures in the 1995 computer-security pursuit.

From network traces to a Raleigh apartment

Investigators followed digital evidence across providers and locations. In the final stage, cellular direction-finding helped narrow activity to an apartment complex in Raleigh, North Carolina.

The FBI arrested Mitnick there early on 15 February 1995. The Justice Department publicly credited Shimomura and the San Diego Supercomputer Center with significant assistance.

Competing versions of the chase

Shimomura and journalist John Markoff told the story in the book Takedown. Mitnick and others disputed parts of that narrative, and the chase became entangled with media mythology about hackers.

Whatever the disagreements, the investigation demonstrated a new reality: activity that seemed anonymous online could be correlated with provider records, radio signals and physical surveillance.

The geek lesson

Cyber investigation is rarely confined to a screen. Shimomura combined network analysis, telecommunications knowledge, collaboration and fieldwork—an early example of the multidisciplinary digital forensics used today.