>> there was a specific part of the design, which i'll refer to here as an "s" shape or a stylized 7 that became very apparent in the photograph. that really piqued my interest. >> but forensic investigator jerry webb had a problem. he needed to know if the weight of a 350-pound man created a different kind of a shoe impression on a tomato than one that you get by copying a shoe impression on paper or a transparency. so webb designed an experiment. >> i had a person that wore size 13 shoes put on a bomb suit and i added weights to the bomb suit in trying to increase the weight of this person to be more close to the weight of the suspect in this case, jim brown. >> webb sprayed water on tomatoes to simulate the rainstorm on the night of the murder.