And with enough legal skill – and financial resources – defendants can marshal armies of experts to undermine prosecution witnesses’ interpretation of forensic data – from the timing of a Google search to the movement of a human body.
“With technology advancing at such a rapid pace, things that we once thought were black and white are no longer black and white,” says Christina Miller, a professor at Suffolk Law School who previously focused on digital forensics cases as a prosecutor in Suffolk County.
She pointed to two recent rulings by the Massachusetts Supreme Court, each upholding decisions barring the use of certain data as evidence because its accuracy was questionable: In 2021, courts prohibited a defendant’s speed from being calculated by a GPS device, and earlier this year, courts prevented evidence of a defendant’s cellphone location history from being introduced in a criminal trial.
In the latter case, the prosecution’s analysts had used a different version of an iPhone’s operating system to replicate the data. This underscored one of Miller’s key points: “The forensic examiner is only as good as the tools he uses, and the tools are only as good as the data.”
Further legal proceedings are to be expected, she said.
Michael Kendall, a former federal prosecutor who now works as a criminal defense attorney, added that judges need to be “much more discerning” in assessing the validity and credibility of someone claiming to be an expert, and what scientific evidence and procedures are rigorous enough to be considered admissible evidence.
“There has been so much false scientific evidence that has fooled people over the years,” he said. “There has to be some validation of the expert. The court has to control the quality of the experts and the quality of the science.”
The reliability of certain digital forensic data depends on the type of technology involved. Programs are designed to perform specific functions, not to serve as official, time-stamped records of events that could constitute irrefutable evidence, for example, said Seth P. Berman, a criminal defense attorney and former prosecutor. While emails, Google searches or phone calls may contain a time stamp, that doesn’t mean the time stamp itself is accurate.
“The whole field of computer forensics is basically an accident,” says Berman, who heads the privacy and data security group at the Nutter law firm and previously worked for a firm specializing in digital forensics. “Nobody designed computers with the goal of creating evidence.”
He added: “As a result, the data is not so clear. There are a lot of things that can just go wrong” and lead to different expert interpretations.
Take the case of Read, for example. She was accused of driving her Lexus into her boyfriend, Boston police officer John O’Keefe. SUV after a night of drinking in 2022 and left him to die outside a Boston police colleague’s home in Canton during a snowstorm. Her defense team claims she is being blamed and that O’Keefe was actually beaten by people attending a gathering at the house and then abandoned outside. Read found O’Keefe’s body hours later in a snowbank after returning to look for him.
The case ended in a mistrial in July; a retrial is scheduled for January.
Central to the defense theory is the timing of the Google search for “Hos (sic) long to die in cold” by Jen McCabe, a woman who was present at the meeting at the Cantons’ home. According to an expert hired by the defense, data shows she Googled the request on her phone at 2:27 a.m., hours before O’Keefe’s body was found. Many of Read’s supporters, who regularly gathered outside the courthouse, cited the statement as a crucial clue to her innocence.
However, prosecution experts said the statement was false and that the search took place after Read and McCabe found O’Keefe’s body shortly after 6 a.m. The discrepancy, prosecution witnesses said, stemmed from confusion about what the time stamp referred to; they said the 2:27 a.m. stamp referred only to the time of the the website that was later used for the search was accessed first.
There were also differing opinions on other pieces of evidence, such as whether or not the calls were deleted from the phone; how fast Read’s car accelerated in reverse; O’Keefe’s movements based on data from his phone and watch.
Read’s legal team built an aggressive defense, cross-examining most government witnesses and also bringing some of their own witnesses to court.
A judge declared the trial void after the jury said it could not agree and reach a verdict. Read maintains her innocence.
Berman noted that most of the defendants do not have the financial resources of Read, a financial analyst and adjunct professor who also benefited from donations from his ardent supporters. A defense with less time, manpower and money likely would not have been able to fight inconsistencies in the data as vigorously, he said.
Ultimately, judges are the arbiters of the credibility of an expert or the validity of a science, guided by decisions of the appellate courts, including precedents of the U.S. Supreme Court. The goal is to “separate science from junk science,” says Rosanna Cavallaro, a Suffolk law professor who teaches about evidence. But that can be difficult, she says, as new technologies and expertise in those technologies evolve.
Cavallaro also said that a “battle of the experts” can harm a case if the process boils down to each side simply looking for the cheapest expert they can find – someone who can not only reach the desired conclusion but also communicate it in an appealing and effective way.
Sometimes, she said, “there is a fear that the person’s opinion can be bought. This problem is widespread in all sciences.”
Sean Cotter can be reached at [email protected]. Follow him @cotterreporter.
