Need help with IRAC. Focus argument using IRAC paragraphs

Scenario:

On New Years Eve 2014, Tyler Durden went to a friend's party. The party was at a fraternity house near his university. While there, he met a fellow student, Marla Singer. The couple hit it off, and began seeing one another. They spent a lot of time at one another's apartments. During this time, Tyler was living on campus with his brother, Jack Durden. Jack was always friendly to Marla, but when he was alone with his brother, Jack would warn Tyler about Marla, saying things like, "You're too good for her, man." Tyler always thought that his brother was just jealous. On June 4, 2015, Marla called Tyler and ended their relationship. Tyler didn't see this coming, and he was devastated. On June 6, Marla received an email from "fightclub123 @ gmail " that read, "You are being watched. Be careful." She deleted the message, and didn't think anything of it. On June 8, Marla received an email from "jackripper @ gmail " that read, "Don't ignore me." Feeling scared, she reported both emails to the authorities. On June 10, police respond to a noise complaint at Tyler and Jack's apartment. Knocking on the door, the officers can hear loud music coming from inside. Jack turns down the music, opens the door, and a cloud of marijuana smoke surrounds the officers. The university has a strict "zero tolerance" policy for marijuana on campus. The officers ask Jack if they can search his apartment, and he consents. Entering the living room, they find a partially burned marijuana cigarette next to a large bag of marijuana on the coffee table. They ask Jack if there are any more drugs in the apartment, and he responds, "In the kitchen." Continuing their search, the officers move to the kitchen. Opening a cabinet, an officer discovers several shrink-wrapped bags of marijuana. While reaching down to open a second cabinet, an officer accidentally bumps the kitchen table. This causes Tyler's computer, a MacBook Pro, sitting open on the table, to "wake up." On the screen appears what is obviously an image of child pornography. The officers seize Tyler's computer. Jack is arrested for possession of marijuana with intent to distribute. During a search of Tyler's computer back at the station, it is discovered that his IP address is the same IP address from which the emails to Marla Singer came from. Tyler is indicted on federal child pornography charges, and two counts of email harassment. Jack's computer, a MacBook Air, was seized from his apartment bedroom and is also in evidence. Jack's computer was password protected, but Tyler's was not. At trial, the government attempts to authenticate the emails as Tyler's using circumstantial evidence. As Tyler's lawyer, it is your job to persuade the judge otherwise. (250 w)