Behind-helmet blunt trauma (BHBT) events transfer energy to the skull and brain, leading to injuries such as skull fracture and traumatic brain injury. The presence of a cranial fracture has been shown to be associated with a higher incidence of intracranial lesions, neurological deficit, and poorer medical outcomes. Therefore, it is important to understand the effect of blunt indentation loading on skull deformation and fracture. Human skullcap specimens were fabricated from postmortem human subjects. They were loaded to replicate blunt impact at both low and high loading rate to quantify the skull mechanical deformation response, as well as associated damage and fracture initiation mechanisms. The specimens were characterized using high-resolution microcomputed tomography (25-m voxel resolution) to understand structural deformation, damage, and fracture that occurred in the skullcap specimen during loading. These experimental measurements are used to understand the mechanical response and include subsequent fracture initiation of the complex 3-D human skull structures. The data and insight gained from this study have been used to develop deformation and failure criteria for use in computational models, in addition to validation of material model and computational methods.