The Dead Girl (2006) on Netflix

When the middle-aged Arden finds the dead body of a young woman dumped in her property in the rural area in Los Angeles, she calls the police and becomes famous in the local town. While shopping in the supermarket, Arden meets the employee Rudy that invites her for a date. Arden accepts the invitation of the stranger and faces her dominating abusive mother and moving from her home to a new town. While preparing the body to the autopsy in the morgue, the depressive coroner Leah believes she is her sister missing for fifteen years, and she accepts for the first time the invitation for a party in the house of her colleague Derek. She changes her behavior and attitude; however, when she discovers that the girl is actually called Krista, she tries to convince her mother Beverly to accept that her sister is dead. Meanwhile, an old woman finds evidences in the storage where her husband works that he may be a serial killer. The mother of Krista, Melora, goes to the precinct and snoops on the documentation the last address of her daughter. She visits the place and meets the roommate of Krista, the prostitute Rosetta, and discovers that she has a three year-old granddaughter, Ashley. Last but not the least, the last day of Krista is disclosed including the identity of her killer.