The unknown suspect stole a dolly and a box labeled "Exempt Human Specimen." The box was full of human heads meant to be used for medical research.
The box also bore a "Science Care" label, KDVR reports. Science Care is a program for donating bodies to science for research and education purposes.
At this point no arrests have been made, and investigators are working to gather more information and recover the stolen human remains, Denver police said on Saturday.
Should someone find the box containing human heads discarded or abandoned, authorities are asking that they immediately call the Denver Police Department at 720-913-2000. If anyone has additional information, they're encouraged to call the Metro Denver Crime Stoppers at (720) 913-STOP(7867). Tips can be submitted anonymously.