BATON ROUGE - New court documents filed ahead of the trial for one of two men accused of kidnapping and murdering an elderly couple reveals new details surrounding the disturbing case. 

Denis and Suzanne Duplantier were beaten, bound and taken from their home on Highland Road in 2015. Their bodies were later found inside their abandoned vehicle at a Hammond truck stop. Family members had contacted law enforcement after not hearing from the couple for some time.

Investigators believe Ernesto Alonso, a handyman who lived on the Duplantier's property, carried out the grisly murders with the help of  Frank Garcia and stole money from the couple's safe. Alonso was found days later at Garcia's Florida home, where detectives also found items stolen from the Duplantier home.

New documents were filed this week revealing new details ahead of the start of Garcia's trial next week.

Those filings reveal that local police in Hollywood, Florida found some of the Duplantiers' jewelry on the front patio of Garcia's home when they first arrived. The Duplantiers' daughter also revealed to investigators that her father previously hid cocaine in his house, though it's unclear how much was kept in the residence. It was also said that officers used a cell ping and historical phone data to track Garcia.

In July, police turned over even more evidence to prosecutors over five years after the killings. Among that evidence is neighborhood security video, more than 20 pages of detective case notes, a smart phone belonging to Alonso, and video of Garcia and his wife in Florida. 

DA Hillar Moore said language barriers, changing venues and the resignation of one of the defense attorneys has dragged out the process of having the case prosecuted.

Garcia's trial is set to begin Sept. 27. Alonso will be tried separately later.