Prosecutors have dropped murder charges against a woman charged in the slaying last year of a Reserve couple who were bound with blue rope and dumped into the Intracoastal Waterway in New Orleans East.

Brittany Martin, 25, pleaded guilty to obstruction of justice Jan. 30 and appears to be cooperating against her codefendants in the February 2014 killings of Lekeitha and Kenneth Joseph. Martin, a former state prison guard, was released on $30,000 bond as she awaits sentencing, according to court documents.

Authorities have said the Josephs were the victims of a well-plotted crime involving an attempted cover-up. Their bodies had been weighted down in the water by 30-pound kettle bells, court documents show.

According to police, Martin had been caught on a surveillance camera purchasing two kettle bells, blue utility rope and other materials investigators believed to be related to the killings.

Charged with murder in the case are Kenneth Joseph’s cousin, Horatio Johnson, 38, and Steven Bradley, 29. A fourth defendant, Frank Mike Jr., 45, has been charged with trying to get rid of evidence.

Mike allegedly drove a van containing the victims’ blood to suburban Atlanta and abandoned it there. Kenneth Joseph had borrowed the 2010 Dodge Caravan from his sister shortly before he and his wife went missing.

A pre-trial conference in the case has been scheduled for Thursday.