The brother of a woman slain in a high-profile, cold case Baton Rouge murder is trying to get his hands on the complete investigative record in her death.

Rodney R. Washington, the brother of Denise Porter Washington, is using the same law that led to the recent release of the files to the man police have identified as a suspect in her killing.

Denise Porter Washington was found stabbed to death March 14, 1985 in the apartment she shared with her then husband, attorney Joel Porter. Her brother argued in a filing to the 19th Judicial District Court this week that he’s entitled to see the complete investigative files under the state’s public records law.

The move comes just under a month after Joel Porter was granted access to all law enforcement reports, photographs and evidence in the killing using the same legal provision Washington cited, which says immediate family members may obtain records into an unnatural death after 10 years have elapsed.

Joel Porter, who has sued the Baton Rouge Police Department for defamation after an arrest warrant surfaced describing him as a suspect in the murder, said last month he would hire top independent investigators to re-examine the case.

Clifton Ivey, Washington’s lawyer, said his client’s goal in requesting the records is to “find out what happened to his sister and how the investigation with the Baton Rouge Police is going.”

Joel Porter’s attorney Steve Irving said in an email he and his team are still reviewing the evidence, which includes physical materials in the custody of the police department.

Advocate staff writer Maya Lau contributed to this article.