On Monday, a US federal appeals court sided against a former Philadelphia police officer who has been in jail 17 months because he invoked his Fifth Amendment right against compelled self-incrimination. He had refused to comply with a court order commanding him to unlock two hard drives the authorities say contain child porn.

The 3-0 decision (PDF) by the 3rd US Circuit Court of Appeals means that the suspect, Francis Rawls, likely will remain jailed indefinitely or until the order (PDF) finding him in contempt of court is lifted or overturned. However, he still can comply with the order and unlock two FileVault encrypted drives connected to his Apple Mac Pro. Using a warrant, authorities seized those drives from his residence in 2015. While Rawls could get out from under the contempt order by unlocking those drives, doing so might expose him to other legal troubles.

In deciding against Rawls, the court of appeals found that the constitutional rights against being compelled to testify against oneself were not being breached. That's because the appeals court, like the police, agreed that the presence of child porn on his drives was a "foregone conclusion." The Fifth Amendment, at its most basic level, protects suspects from being forced to disclose incriminating evidence. In this instance, however, the authorities said they already know there's child porn on the drives, so Rawls' constitutional rights aren't compromised.

The Philadelphia-based appeals court ruled:

Forensic examination also disclosed that Doe [Rawls] had downloaded thousands of files known by their "hash" values to be child pornography. The files, however, were not on the Mac Pro, but instead had been stored on the encrypted external hard drives. Accordingly, the files themselves could not be accessed.

The court also noted that the authorities "found [on the Mac Book Pro] one image depicting a pubescent girl in a sexually suggestive position and logs that suggested the user had visited groups with titles common in child exploitation." They also said the man's sister had "reported" that her brother showed her hundreds of pictures and videos of child pornography. All of this, according to the appeals court, meant that the lower court lawfully ordered Rawls to unlock the drives.

"The Magistrate Judge did not commit a clear or obvious error in his application of the foregone conclusion doctrine," the court ruled. "In this regard, the Magistrate Judge rested his decision rejecting the Fifth Amendment challenge on factual findings that are amply supported by the record."

The suspect's attorney, Federal Public Defender Keith Donoghue, was disappointed by the ruling.

"The fact remains that the government has not brought charges," Donoghue said in a telephone interview. "Our client has now been in custody for almost 18 months based on his assertion of his Fifth Amendment right against compelled self-incrimination."

A child-porn investigation focused on Rawls when the authorities were monitoring the online network, Freenet.

The decision from the appeals court comes as encryption is becoming more common on mobile phones and computers. What's more, encryption has seemingly become part of the national political discussion concerning whether governments should demand that companies bake backdoors into their encrypted products so that authorities can access content on encrypted devices.

The Supreme Court has never ruled on the forced decryption issue. A different federal appeals court, the 10th US Circuit Court of Appeals based in Denver, ruled in 2012 that a bank-fraud defendant must decrypt her laptop. The order wasn't enforced, however, as the authorities eventually accessed the laptop without her assistance.

The contempt-of-court order against Rawls was obtained by authorities citing the 1789 All Writs Act. The All Writs Act was the same law the Justice Department asserted in its legal battle with Apple, in which a magistrate judge ordered Apple to produce code to enable the FBI to decrypt the iPhone used by one of two shooters who killed 14 people at a San Bernardino County government building. The government dropped the case when authorities paid a reported $1 million for a hack.

"Unless the suspect unlocks the drives or a court unwinds the order, he will remain jailed," Marc Rumold, an Electronic Frontier Foundation staff attorney who filed a friend-of-the-court brief in the case, said in a telephone interview.

In that brief, the EFF said "compelled decryption is inherently testimonial because it compels a suspect to use the contents of their mind to translate unintelligible evidence into a form that can be used against them. The Fifth Amendment provides an absolute privilege against such self-incriminating compelled decryption."

The authorities, however, said no testimony was needed from Rawls. Rather, they said, (PDF) "he can keep his passwords to himself" and "produce his computer and hard drives in an unencrypted state."