We present a unique case of a four-week-old boy who died of a severe hypoxic encephalopathy due to a subdural hematoma. A week before his demise, a small left sided parieto-occipital subdural hemorrhage was seen on both CT and MRI. On the right side a larger, fronto-parietal subdural hemorrhage was present with a prominently defined protuberance to the right hemisphere, causing a midline shift to the left. Subdural hematomas have a broad differential diagnosis, including abusive head trauma which can have far reaching consequences. In order to diagnose the underlying cause of the subdural hematoma, and subsequently confirm or refute the differential diagnosis, a medicolegal autopsy was ordered. The autopsy revealed a rare primary intraosseous vascular malformation of the skull, at the location of the subdural hematoma. This, in combination with the coagulation disorder due to alpha-1-antitrypsin deficiency, was considered to be the underlying cause of death.