A prosecutor disclosed Tuesday which of two men will be tried first in the 2015 robbery, beating, kidnapping and strangling of a Highland Road couple in their 70s.

Cousins Frank Garcia and Ernesto Alonso are charged with first-degree murder in the slaying of Denis "Bubbie" Duplantier, 71, and Suzanne "Suzy" Duplantier, 70.

Their bodies were found in the back seat of their red pickup at a Hammond gas station.

Garcia, 53, will be tried first on Sept. 27, East Baton Rouge Parish Assistant District Attorney Dana Cummings told state District Judge Tiffany Foxworth.

Alonso, 48, who did landscaping work for the Duplantiers and lived on other property owned by them, will later be tried separately.

Garcia's attorneys have claimed in previously filed documents that he and Alonso have antagonistic defenses, and the lawyers anticipate that Alonso will try to "shift blame from himself to Garcia" at trial.

Alonso's white pickup was captured on surveillance video as it followed the couple’s vehicle into the Petro truck stop, authorities have said. Alonso’s truck was later discovered at Garcia’s residence in Hollywood, Florida.

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A safe inside the Duplantier home was found open, with cash missing. Blood was located in several rooms.

Authorities believe the two men entered the Duplantier home and beat them to get the information needed to open the safe.

A large amount of cash and a number of unspecified items believed stolen from the home were found at Garcia’s home in Florida, authorities said.

Prosecutors announced in 2016 they would not seek the death penalty against either man after discussions with the victims' families.

They face mandatory sentences of life in prison if convicted as charged.

Issues with lawyers, evidence and appeals have scuttled previous trial dates in the case.

Email Joe Gyan Jr. at jgyan@theadvocate.com.