Where did Nick get the blood to stage his death?

I don't think that he would've been stupid enough to cut himself on scene since he would've needed a lot of blood and that kind of a cut on the scene would be a bad idea. I guess the only explanation is prior to the faking of his death he was drawing some of his blood a little bit at a time and storing it to use afterwards. He would have to use his own blood to make sure the CSI investigators(if they had them back then) wouldn't be able to took a whole in the coverup.