Erik the Red was too violent, even by Viking standards.
And it may have been genetic. As a result of his father having committed manslaughter, he and the rest of his family were forced to move from Norway to Iceland in 960 AD. Erik did pretty alright for 20 years, until some of his thralls were killed by a neighbor. That incident set a sort of murder spree in motion, which resulted in Erik getting his ass kicked out of Iceland in 982 AD.