TUPELO (AP) — Authorities say a Mississippi woman signed for a package at the post office that contained marijuana.

Lee County Sheriff Jim Johnson tells news outlets that 48-year-old Angel Herndon walked into the post office and signed for the package. Authorities say she was immediately arrested when she walked outside Friday.

Authorities say an undercover investigation led to information that someone was going to get a large package containing drugs. The package contained more than 15 pounds of marijuana.

Herndon was charged with possession of marijuana with the intent to distribute. Authorities say charges against her are likely to be enhanced due to the post office’s proximity to a high school.

More arrests are expected as the investigation continues. It’s unclear if Herndon has a lawyer.