People with better qualifications, higher-powered jobs and higher incomes are known to be at less risk of being murdered. However, there have been no studies into whether intelligence per se affects one's likelihood of being killed. A Swedish study looked at a group of 968,864 men who had served as military conscripts between the ages of 18 and 19. The men had taken IQ tests as part of their medical assessment when they were conscripted and were tracked over the next 20 years. 191 of them were murdered. A high IQ score was associated with a halving of the risk of being murdered and the higher people's IQ was the lower their risk.
Batty, G. David ... [et al] - IQ in early adulthood and later risk of death by homicide: cohort study of 1 million men British Journal of Psychiatry 193(6), 438-443