MacDonald spent nearly nine years after her daughter's murder plastering Debi's picture on billboards, pizza boxes, and even shopping carts in hopes of catching the killer.
MacDonald: "In the beginning, it was because I was her mother and no one was going to murder my kid and get away with it."
Her fierce determination finally paid off in 1997 when an informant's tip led to the arrest and conviction of the man who stabbed and then raped her daughter.
MacDonald's tragedy also inspired her to start local television and radio programs to help other victims' family members, including the mother of murdered Washington intern Chandra Levy. Chandra's remains were found in 2002, but her case is still unsolved.
Susan Levy: "I always have hope, and hope that someone will come out of the woodworks and realize that their child or their loved one could have ended up like my daughter."
Levy and Boni Driskill came from Modesto to support MacDonald on this difficult anniversary. Driskill says MacDonald has also helped keep up the search for her own daughter's killer. Lacy Ferguson a single mother was murdered in a drive-by shooting in Modesto back in 2003.
Boni Driskill: "She's been a guiding light for me. Me and I can't count how many others she's helped."
But MacDonald's work is still not done. She's passionately pursuing legislation in California that would make it a crime to rape someone after a murder. Her daughter's killer received a plea deal because there's currently no special penalty for such an act.
MacDonald: "No mother should have to go through that. It won't help Debi, but it will help other families."