The last two defendants charged in the 2013 murder of Leighton Powe in Slidell have been handed lengthy prison terms — 27 years for alleged ringleader KiShion Griffin and seven years for Darion Causey, who helped cover up the crime after it had been committed.

On Nov. 24, Griffin, 20, pleaded guilty to manslaughter, according to Lisa Page, a spokeswoman for 22nd Judicial District Attorney Warren Montgomery’s office. The 23-year-old Causey pleaded guilty Monday to obstruction of justice, Page said.

The killing happened on Sept. 7, 2013, when three men met the 22-year-old Powe behind a Dollar General store, ostensibly to buy marijuana. Instead, prosecutors said, the three accomplices had plans to rob him, and when Powe climbed into Trenton Johnson’s truck, Bobby Isidore grabbed him from behind. A struggle ensued, and Felix Adams fired the shot that hit Powe in the head.

The men dumped Powe’s body along Javery Road near Slidell. Johnson later reported his truck as stolen, and Causey helped to burn some of the clothes the group had worn during the incident.

Griffin has maintained he was not present at the robbery.

Johnson pleaded guilty in 2014 to manslaughter and agreed to testify against the others, including Griffin, who he said orchestrated the robbery plot while Johnson and the others played video games. Johnson was sentenced to 25 years.

Adams and Isidore were both convicted by juries of second-degree murder. Adams was sentenced to life plus 20 years and Isidore was sentenced to life in prison earlier this year.