Detectives investigating the deaths of a brother and sister found next to an interstate in Gwinnett County are searching for two men suspected of playing separate roles in the case.

Maria Rosaria Montes Dorantes, 23, and her brother, 16-year-old Juan Angel Montes, were found dead from gunshot wounds in the grass near the I-85/985 split Sunday evening, Gwinnett police said. After releasing photos of the siblings and requesting tips Thursday, investigators have filed charges against 42-year-old Manuel Lorenzo Sanchez and 24-year-old Ricardo Lorenzo Montes.

Sanchez is suspected of killing Maria and Juan Montes, police said. He will face two counts each of felony murder, aggravated assault and possession of a firearm during the commission of a crime.

Ricardo Montes, who police say was not related to the siblings, is charged with tampering with evidence.

Police said the whereabouts of Sanchez and Ricardo Montes are unknown and released photos of the two suspects. Investigators are again asking the public for help as they work to locate the men.

Anyone with information is asked to call Gwinnett detectives at 770-513-5300. To remain anonymous, those with information may call Crime Stoppers at 404-577-TIPS (8477) or visit www.stopcrimeATL.com. Tipsters can receive a cash reward for information leading to an arrest and indictment in this case.