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How digital evidence supported gerrymandering claims

Earlier this month, I had the once-in-a-lifetime opportunity to travel to the United States Supreme Court to witness the headline-making gerrymandering oral arguments out of Wisconsin. Some people are calling this case the most important of the year, with enormous potential consequences for political redistricting and any number of similar cases in which gerrymandering claims play a part.

During a five-month period in the Senate in 2012, the Democratic party made the most of its short-lived majority to gather digital evidence in support of their extreme gerrymandering claims against the Republicans. I was asked on behalf of the Campaign Legal Center in Washington, D.C. to provide digital forensic analysis of hard drives that had been gathered from Wisconsin lawmakers. These hard drives had been used by the mapping drafters and ultimately showed that one party had worked to gain a clear advantage, even in the event that they did not win a majority of votes. My analysis led to the discovery of several key deleted files, including deleted spreadsheets, that revealed a systematic pattern of intent: The metadata revealed that with each draft of the spreadsheets, the map-drawing lawmakers attempted to strengthen their party’s majority and retain control.

Does delete mean deleted?

Upon my initial review of the hard drives provided, it became clear that a large number of files had been deleted immediately before the digital evidence had been delivered to my office. It is interesting to note that even at the state Senate level, key players in this case didn’t understand that delete doesn’t always mean deleted. I determined (and later testified) that hundreds of thousands of files had been deleted using a commercial wiping program in the week prior to the computers being turned over to Wisconsin Senator Mark Miller.

The Campaign Legal Center’s request for an independent forensic investigation was instrumental in constructing this case. Seeing that fraud or some kind of misconduct had most likely taken place, the court granted the request, which ultimately led to my review of the hard drives in question. The pattern of purposeful wiping further confirmed suspicions.

A second review of the digital evidence

After the first case settled out of court in 2013, I was approached again to conduct another limited analysis of the hard drives to uncover more relevant digital evidence. As attorneys built their case for the United States Supreme Court, digital evidence continued to play a key role in unraveling a narrative of purposeful, extreme gerrymandering on the part of one of the political parties.

This subsequent analysis of the provided hard drives led to the uncovering of several deleted spreadsheets, and detailed the redistricting map drafters’ plans to gain a 54-45 projected majority over the other political party, regardless of whether or not they actually won the majority of votes. One particularly damning spreadsheet, labeled “Tale of the Tape,” demonstrated that the minority political party in Wisconsin would need at least 54 percent of the vote to gain an Assembly majority. Clearly, the map drafters had been attempting to manipulate the mapping as much as possible to put the minority at an extreme, and perhaps unconstitutional, disadvantage.

My subsequent examination of the digital evidence also revealed some critical metadata, data which may have been overlooked had the plaintiffs opted for a simple e-discovery procedure over digital forensics. Metadata is a term used to describe “data about data,” and in this instance, the critical metadata consisted of timestamps. The creation dates of the maps located on the hard drives, and their associated revisions, allowed for the reconstruction of a timeline revealing that with each round of revisions, the maps’ drafters were purposefully solidifying their majority. It should be noted that these maps would determine which political party would be in control for a span of over 10 years. The stakes were high, and as with many forensic analyses, the devil was in the details.


The opportunity to play a role in a Supreme Court case was an amazing experience, and it served to underscore some of the things I know to be true about digital evidence. The faster you can gather it and preserve it, the better. The plaintiffs made the absolute most of their temporary majority in the Senate. Prioritizing the collection and preservation of digital evidence was a strategic move that showcased the profound impact of digital evidence in shaping the course of a case. In this instance, it could have nationwide consequences for gerrymandering and political mapping. Apart from the political consequences, I think this is a clear-cut example of how digital evidence can make a case by serving as an impartial witness in court. As if that weren’t enough, I also sat directly behind Arnold Schwarzenegger during the arguments.


MARK LANTERMAN is the chief technology officer of Computer Forensic Services. A former member of the U. S. Secret Service Electronic Crimes Taskforce, Mark has 28 years of security and forensic experience and has testified in over 2,000 cases.

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