I would posit that the percentage of White serial killers has dropped as technology improves- and becomes more publicly known- is because Whites can learn and practice self-control. Blacks cannot.

They can't control their impulses, they don't understand police investigative techniques, they don't understand science. Many blacks still don't understand that police radar sets can work front, back, and moving. They still aren't prepared for security cameras. DNA is well, well beyond their comprehension.