55 years ago, the first computer search warrant was issued — in February 1971, a Santa Clara judge authorized police to seize punch cards and a 'computer memory bank'

Source: Tom’s Hardware

First computer search warrant (1971)

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55 years ago, in a courthouse serving the San Jose‑Milpitas district of Santa Clara County, a judge for the first time signed a search warrant that treated a computer system as something that could be searched and its content seized. Dated February 19, 1971, the order authorized Oakland Police to enter offices in Palo Alto and homes in Menlo Park to look not just for papers but also for data stored on machines.

The case involved University Computing Company and a program described in court documents as a remote‑plotting system (a trade secret) valued at $15,000, or around $120,000 today. In his affidavit, Sgt. Terence Green requested authority to seize “computer memory bank or other data storage devices,” along with “computer printout sheets,” language that shows how investigators were grappling with the concept of intangible property at a time when most computing infrastructure filled entire rooms.

Central to the dispute were punch cards, the dominant medium for program storage and job submission at the time. The affidavit describes “a deck of key punch cards” tied to the remote plotting program. Each card represented a line of code or data, meaning a full program could be made up of hundreds or thousands of cards that had to be meticulously kept in order.

The warrant itself was later reproduced in Jay Becker’s The Investigation of Computer Crime (National Center on White‑Collar Crime operational guide). A copy of an “actual state search warrant” appears in Appendix 5 of the report.

Early digital forensics

Becker’s manual offers a glimpse into how investigators in the early 1970s were already wrestling with now‑routine problems in digital forensics. In the section titled “The Nature of Computerized Evidence,” he notes that evidence in a computer is “more ‘dense’ than in any other information system,” describing how a single computer tape can contain as much information as “a shelf full of books.” Much of that information, he explains, is invisible without translating the machine‑readable symbolism into print.

According to the reproduced documentation, investigators conducting the February 1971 search didn’t simply remove hardware; they generated printed directories of files stored on the system and produced magnetic tapes to preserve the contents. Becker emphasizes that in some cases it may be “desirable, if not necessary, to duplicate the controls” of each information‑storing device—whether tape, disk, or card—so that subsequent changes cannot compromise the evidentiary record.

Becker also warns that search warrants in cases involving computers must be narrowly defined because the system may contain “an enormous amount of description for the investigator to cover each component of the computer system which he seeks to inspect or seize.” That concern about overbreadth and technical unfamiliarity later became a foundational concept in jurisprudence concerning digital search and seizure.

More than half a century later, storage media and network architectures have changed beyond recognition, but the underlying problem identified by Becker has not. Crime taking place in and evidenced by the digital domain now dominates the newswires.