Police say the original investigations into these deaths failed to identify the remains of Jane Doe and Janet Doe or determine a suspect.
New renderings based on Snapshot DNA Phenotyping of Jane Doe in May 2016 and Janet Doe in May 2017 gave detectives insight into the victims' features as well as genealogy.
RELATED: Renderings show faces of 2 homicide victims both found on road in League City
In April 2018, detectives worked with the FBI to build the family trees of the women. They then compared the profiles of the victims against the Family Tree DNA database.
On January 29, 2019, the FBI gave the League City Police Department the results of those comparisons and were eventually able to identify and locate family members of those victims.
The billboards are asking anyone with information on the murders of Donna Prudhomme and Audrey Lee Cook to come forward.
The billboard campaign officially kicks off Tuesday.