An Orleans Parish grand jury on Thursday indicted three people in the slaying of a Reserve couple who authorities say were bound with blue rope and dumped into the Intracoastal Waterway in New Orleans East in February.

A fourth man was indicted for his alleged role in a botched attempt to cover up the killings.

Along with Horatio Johnson, 38, and former state prison guard Brittany Martin, 25, who were previously booked in the murders, the indictment also names alleged conspirator Steven Bradley, 28, in the killings.

The bodies of Lekeitha and Kenneth Joseph turned up in February, victims of what authorities have described as a well-plotted crime in which others tried to cover up the evidence of their deaths left behind in a 2010 Dodge Caravan. Kenneth Joseph had borrowed the vehicle from his sister shortly before his and his wife’s disappearance.

Blood found in the van tested positive for a mix of the couple’s blood. The two were reportedly weighed down in the water by 30-pound kettle bells.

Until the indictment, Bradley had been booked only with obstruction of justice and conspiracy to obstruct justice. The indictment names him in both murders, although his alleged role is unclear.

According to an arrest warrant for Bradley, he and a man identified as “Blue” received the Caravan from Johnson, who is a cousin of Kenneth Joseph. Johnson asked them to “clean it out and get rid of it for him,” the warrant states.

Bradley told detectives he drove the van with “Blue” to the home of Frank Mike Jr., a New Orleans man who admitted driving it to suburban Atlanta and abandoning it there, according to the FBI.

The five-count indictment also accuses Mike, 45, of conspiracy to obstruct justice by tampering with evidence in the case, as well as obstruction of justice and being an accessory after the fact to murder.

Johnson, Martin and Bradley also are accused in the two obstruction counts.

Criminal District Court Judge Karen Herman set bail for Johnson, Martin and Bradley at $2.5 million apiece. She set Mike’s bail at $700,000.