ST. TAMMANY PARISH -- The St. Tammany Parish Sheriff's Office Facebook page says that four people have been arrested in connection with the murders of Pearl River friends Raegan Day and Dustin Hartline.

ALSO: Autopsy to determine how friends were killed

The sheriff's office says that "all individuals directly involved in the murders are in custody."

Police arrested 18-year-old Jason Landry, 25-year-old Brittney "Beezy" Savell, 22-year-old Derrion Lemoine and 27-year-old Steven "Stevie" Oliveieri in connection with the double homicide investigation. Landry, Savell and Olivieriare all Slidell residents. Lemoine is a Lacombe resident, according to police.

MORE: Bodies in car in water at boat launch identified as missing Pearl River friends

The sheriff's office says that the investigation is ongoing and more arrests are possible.