Not many Buddhist murderers, but yeah, religion and murderous intentions have no correlation. Muslims have more, just because there are more Muslims, Christians probably have a higher percentage in general because almost none of them actually follow their faith
But Buddhists don't generally have a history of being murderous. You see, an example of how Buddhism and Hinduism settle their differences can be seen in how Shankara handled it. He went around and debated people of various beliefs and won those, therefore curtailing their influence.