>> we did use some light and oblique angles and some ultraviolet light. this is also used when we took photographs of the bun. >> the indentations strongly resemble a right toe, the ball of a foot and bits of the second and third toes. and it looked like there were ridge details in the soft bread that resembled prints. if these were footprints that matched carlos robinson, prosecutors had an open and shut case. >> our suspect dumped the buns on the floor and used the plastic bag to carry out the knife. the buns were fresh, and the barefoot person had also stepped in these hamburger buns. >> but if they weren't robinson's prints, then it raised the possibility of reasonable doubt or the possibility that robinson had an accomplice. >> so it was almost like we had to prove not just that the