How did Vincent trick others into believing he was Jerome?

Vincent successfully deceived others into thinking he was Jerome by using Jerome's blood and urine. This method was essential in a society where genetic identity is paramount and individuals are judged and categorized based on their DNA. In the film "GATTACA," the use of biological samples like blood and urine is crucial because these samples are often tested to confirm identity and genetic integrity. Vincent, being a genetically inferior individual, knew that if he could provide Jerome's biological fluid samples during routine tests, he could avoid detection as an 'Invalid' and present himself as Jerome, a genetically elite individual.

This clever ruse allowed Vincent to manipulate the system that relies heavily on genetic information for social status and employment opportunities. The use of Jerome's biological materials was pivotal, as it not only helped him pass as Jerome in official screenings but also solidified his deception in the eyes of his peers and superiors.