![Shannan Gilbert](https://assets3.cbsnewsstatic.com/hub/i/r/2020/12/13/7f08b078-55f1-4711-b694-cfc1d9620e2f/thumbnail/640x360/264c0860372db945077f30099355cc1f/lisk-shannan-gilbert.jpg?v=d8f7565ef3e8b72561ee316b5993cbf9#)
How a mother's quest to find daughter led to eventual arrest of Gilgo Beach murders suspect
Mari Gilbert, in the final years of her life, pressured police to take her daughter's disappearance seriously. She fought tirelessly to ensure that Shannan and the other victims would not be forgotten.