Well there's what Canseco said, there's the bottle of steroids that was sitting in his locker, there's common sence, and there's the "I'm not here to talk about the past" crap he pulled on Capitol hill. McGwire, Sosa, Bonds, ect. all juiced, and we all know it.
The single season HR record stood for decades, then all of the sudden it gets broken 5-6 times? And as soon as they start really start testing (now), no one has come close to getting 61 HR's in a season.
If it looks like a duck, quacks like a duck, and sh*ts on your car like a duck, then it's a duck. I don't need blood tests to tell me that.