。
The bloodstains on the road must be mine.
Literal
Road [possessive-の] bloodstains [topic-は] mine [copula-に] must-be.
血痕 (けっこん, 'bloodstain') is formal/forensic vocabulary. 俺 (おれ) is rough masculine first-person. に違いない ('must be, there's no doubt') expresses strong certainty. The combination of rough speech and forensic vocabulary creates a dramatic scene.