Scott Heston is the killer of his friend Riley Cuskey, which was allegedly accidental during a recorded session of extreme fighting. It was later revealed that he intentionally struck Cuskey in his leg so that he'd bleed from his major artery, which Heston's girlfriend Denise Pikering, under the alias of Cassandra Sullivan, told SVU they'd learned in science class. Heston was jealous that Pikering had engaged in intercourse with him after Cuskey.
Unfortunately, this revelation didn't come out until after he was tried, so he was only convicted of criminally negligent homicide. While he awaited sentencing, he found out that Pikering was actually a 28-year-old woman and not a 16-year-old teenager. Disgusted, he paid classmate Keith 500 bucks to hit Pikering with his dad's car out of revenge and to keep her from testifying at sentencing. Heston was put on probation for Cuskey's murder, but he was arrested again for paid attempted murder, while Pikering was also placed on trial for statutory rape. When she confronted him on the stand and kept denying her age, he lividly insulted her for her lies and confessed to Cuskey's intentional murder on the stand. He was then taken into custody and found guilty of perjury and conspiracy and imprisoned. (SVU: "Pretend")