[That gets a frown, but it's a contemplative one.]

'Tis possible, yes, but were you the killer would you truly risk leaving evidence behind that has been used in previous trials to identify the culprit? I certainly wouldn't. I would think any killer would be thorough in ensuring their past wound bandaged.

Not to mention, if the blood truly is everywhere as Xie Lian said, that would suggest a far faster rate of loss than our past wounds, yes?

But... you are correct. We should keep it in mind.