A 23-year-old man pleaded guilty to first-degree murder on Thursday for the death of Rosa Sanchez Merino, whose remains were found in a shallow grave last September in Olney. According to the Montgomery County State’s Attorney’s Office, “In the Circuit Court for Montgomery County, MD, before the Honorable Theresa Chernosky, defendant, Roberto Rivera-Delgado, 23, of unknown address, pleaded guilty to first-degree murder, conspiracy to commit first-degree murder, and participating in a criminal organization resulting in death. The plea hearing was held yesterday, July 25, 2024. Rivera-Delgado faces the potential of life in prison. A sentencing hearing is scheduled for June 13, 2025.