A Louisiana state prosecutor who declined to file a murder charge in connection with a man’s drugging and robbery death in 2017 has demanded more than $18,000 for the victim’s grieving father to obtain public records related to the case.

Robert G Arthur III – whose son, Shawn Arthur, died as a result of federal sex trafficking and theft crimes, according to a judge – responded to the demand by filing a lawsuit Wednesday which alleges that the office of Jefferson parish district attorney Paul Connick is violating state public records laws by setting such a high price.

The case as laid out by Robert Arthur illustrates how government agencies can purport to be prepared to release public documents but then erect another impediment to access by using cost-prohibitive pricing. Louisiana news station WWL-TV reported that Arthur’s lawsuit could also have wide implications for journalists and others who have seen authorities charge increasingly high fees for records that are supposed to be accessible by the general public.

“If fees dissuade public-interest requesters, such as citizens and journalists, from acquiring records, then under democratic theory, informed self-governance is threatened, not to mention practical benefits to society,” said Arthur’s lawsuit, which was prepared with the help of a Tulane University law clinic that specializes in issues pertaining to access to government records.

A statement from Connick’s office did not address Arthur’s lawsuit, citing a policy against discussing pending litigation. But the statement insisted Connick’s office “follows Louisiana’s public records law when responding to the public’s requests for documents that are in its custody”.

“The law additionally allows the office to set reasonable fees for providing these documents,” said the statement, which directed members of the public to the agency’s website for information on provisions by which they could seek reduced fees.

The local sheriff’s office at first decided that Shawn Arthur’s death was an accident, opting against following a lead to a sex worker who had visited his apartment in the Jefferson parish community of Metairie on the night he died.

Robert Arthur – who lives near Kansas City, Missouri – later hired private investigators to track down the sex worker, Dominique Berry, in a Georgia jail, where she acknowledged giving drugs and alcohol to dozens of men, including Shawn Arthur, to help her boyfriend Randy Schenck rob them.

As HuffPost reported, Robert Arthur provided his investigators’ findings to federal authorities, who charged Schenck and Berry with sex trafficking as well as identity theft.

Schenck and Berry each pleaded guilty, receiving prison sentences of 25 years as well as three years and nine months, respectively. The judge presiding over the case ordered Schenck to pay Shawn Arthur’s family nearly $330,000 in restitution, an amount meant to represent the victim’s lost net-income, his funeral expenses and his stolen property, which included his credit and debit cards, engagement ring, wedding bands and truck.

Schenck could have also faced a charge of murder because one of the definitions for that crime under state law is a death which results from certain felonies, including robbery.

But, as WWL-TV reported, Connick’s office in February announced that it did not have sufficient evidence for “a homicide prosecution in connection with the death of Shawn Arthur”.

Robert Arthur requested public records about his son’s case the same day of that announcement, according to his lawsuit, which the Guardian reviewed.

In September, the DA’s office indicated that it had 37,000 pages of documents ready for Robert Arthur. And in October, the office told Arthur it could send the files to him if he paid 50 cents a page – about $18,500 – for paper copies.

Arthur said another option presented to him was paying 15 cents a page – more than $5,500 – for digital copies, with the fee meant to cover scanning and redaction of the documents.

Arthur could also travel to the office, review them in-person and take photos or scan them. But that would also be costly. He estimates that he typically spends between $850 and $1,000 to go to Jefferson, which is adjacent to New Orleans, whenever he travels there for matters related to his son’s death.

“To file a request for public records and finally be told … months later that the records are ready, with a price tag of [more than] $18,000, is ridiculous,” Arthur said to WWL-TV.