Rebecca Arellanosa was 22 when she was last seen on May 5, 2001, in the 10700 block of Lawler Street in Los Angeles. Authorities have described her disappearance as occurring under unusual circumstances, but specifics about those circumstances are not provided. She is classified as an endangered missing person and has not been heard from since.

Of Filipino descent and known also as Becky or Monica, she is described as olive complected, with short straight black hair, brown eyes, a mole near her right eye and another on her left cheek. She was 5 feet 3 inches tall and about 120 pounds at the time she went missing. The Los Angeles Police Department is the investigating agency; public information about leads or persons of interest is limited and the case remains unsolved.

Anyone who knew Rebecca, saw her in that neighborhood on May 5, 2001, or has information that could help investigators is encouraged to come forward.