possible semen sample plus a blacklight situation:
Officer
Michaels: "I often go to sleep and dream of waking up in a world where everything's covered in semen."
Officer
Slater: "I mean, who doesn't ?"
Officer Michaels: "It'd be nice. Like that crime scene today."
Officer Slater: "Yeah."
Officer Michaels: "If the man had ejaculated and then punched you in the face..."
Officer Slater: "Yeah."
Officer Michaels: "...we'd have a real good shot at catching him."
Officer Slater: "No way."
Officer Michaels: "Just punched in the face, no semen."
Officer Slater: "Yeah, no semen."
Officer Michaels: "
Story of my life."