LAWRENCE, Kan. -- The mother of a University of Kansas student who was murdered in Costa Rica said she is growing tired of delays in the investigation, KMBC 9 News reported.

Evidence that was supposed to be tested for DNA is missing, U.S. authorities said.

Jeanette Stauffer told KMBC 9 News that she wonders why the Costa Rican government doesn't seem to care about solving the case.

She also said she believes that the U.S. government is doing what it can in the case.