ST. PAUL - The Minnesota Supreme Court heard arguments Tuesday, Sept. 12, on a case that's received national attention: whether - or rather, in what way - someone can be ordered by the government to unlock their cellphone.

While touching on the question of how the law strives to keep up with technology, the case largely revolves around constitutional protections against self-incrimination, or - as the Fifth Amendment puts it - being compelled to bear witness against oneself.

In 2015, a Carver County jury convicted Matthew Diamond of burglary, theft and damaging property. Part of what the jury relied on for its decision was damning evidence found on Diamond's phone.

During the 2014 burglary investigation, Diamond had been jailed on an unrelated case, and his cellphone stored in a property room. The Chaska police detective investigating the burglary obtained a search warrant for the phone but found it to be encrypted with fingerprint access technology.

So the state issued an order to compel Diamond to give a fingerprint, while Diamond's attorney initially argued he shouldn't have to, on Fifth Amendment grounds.

WDAY logo
listen live
watch live

But a district court ruled there was probable cause to support the state order, and Diamond - under threat of being found in contempt - gave his fingerprint.

It's the phrasing of that order, and Diamond's reaction to it, that was the primary focus of attorneys arguing both sides of the case before the Supreme Court on Tuesday.

The order stated Diamond had to "provide a fingerprint or thumbprint as deemed necessary by Chaska police."

When confronted with the order, according to evidence in the case, Diamond then asked officers, "Which finger do you want?"

"The one that opens it," an investigator replied.

State public defender Steven Russett argued that if the order had simply told Diamond to give a fingerprint, then there would've been no Fifth Amendment violation - and no case.

But because his client was compelled to give information about which finger unlocked the phone, he was therefore admitting the phone was his and he had access to it.

The Fifth Amendment protects against compelled "testimonial communications," whereas simply getting fingerprints - which does not require any communication on the part of a suspect - is not protected.

"If the order said, 'You may take his fingerprints,' I wouldn't be here," Russett said.

Put another way, telling police which finger to use - rather than just giving them his hand without a word - "became a communicative act," Russett argued. "The order compels him to tell police what they want to know."

Carver County Attorney Peter Ivy argued that Diamond asked the question about which finger to use on his own.

"He created that situation himself," Ivy said.

And regardless, police already had evidence the phone was Diamond's, Ivy argued: It was found in his possession, he used it to call his probation officer, and another witness stated it was his.

"What is he telling us that we don't already know?" Ivy asked the court.

When the case was initially tried in 2015, the Carver County District Court ruled against the Fifth Amendment argument.

"By being ordered to produce his fingerprint, however, Diamond was not required to disclose any knowledge he might have or to speak his guilt," and added it was "no more testimonial than furnishing a blood sample, providing handwriting or voice exemplars, standing in a lineup, or wearing particular clothing," the district court wrote.

In January, the state Court of Appeals agreed with the district court's ruling.

The Pioneer Press is a Forum News Service media partner.