Legal question: How do you cross-examine a computer?

Post Gazette

In the homicide case against Michael Robinson, accused of killing two people in Duquesne in 2013, the computer program, TrueAllele, found that DNA from a black bandanna recovered near the crime scene was 5.7 billion times more likely his than coincidence.

Mr. Robinson’s attorneys want to know how it is that the program reached the results it did.

“The witness in this case is a computer,” defense lawyer Ken Haber said. “You can’t cross-examine a computer. The Constitution demands, and justice requires, we be permitted to find out what the computer is doing to come up with its answer.”

But when he and co-counsel Noah Geary sought the source code for the program, they were denied. The judge ruled that it could cause harm to Cybergenetics, the Oakland-based company that created TrueAllele, which uses probabilities and statistics to determine if a suspect’s DNA is in a complex biological mixture.

This and other similar cases bring up a key question as probabilistic DNA programs become more prevalent. [MORE]