SALT LAKE CITY — Who left the Barbie doll on Rosie Tapia's grave?

That's the question investigators are asking the public more than 23 years after the 6-year-old was found raped and murdered. Thursday marks what would have been Rosie's 30th birthday.

The Utah Cold Case Coalition has arranged for DNA evidence to be gathered from the doll, which was found on Rosie's grave at the Salt Lake City Cemetery shortly after her burial.

On August 13, 1995 someone removed the screen from a window on Rosie's family's ground floor apartment, near 1700 S and 1700 W, and carried Rosie away. Her body was found in a nearby canal off the Jordan River.

"Two possible persons of interest in the case have been identified who had some fixation with Barbies. But before a costly analysis is performed on the DNA, the coalition is asking whether someone knows who placed the doll on Rosie’s grave," a news release from the coalition said.

On Thursday, the coalition will be providing updates on the Tapia case and other information about the collection of DNA evidence and efforts to encourage police agencies to share data about cold cases more openly. Watch FOX 13 for the latest updates.

Anyone with information on the Rosie Tapia case is urged to call 385-258-3313 or email whokilledrosie@gmail.com.