Utah County District Attorney Jeff Gray announced Tuesday that prosecutors will be seeking the death penalty against 22-year-old Tyler Robinson, who is accused of murdering conservative activist Charlie Kirk during an event at Utah Valley University on Sept. 10.Calling the killing “an American tragedy,” Gray said Kirk was gunned down while exercising a fundamental American right — "the free exchange of ideas in search of truth, understanding, and a more perfect union."“Charlie Kirk was first and foremost a husband and father to two young children. He was a son, a brother, and a friend,” Gray said.“Like all murders, the senseless taking of Charlie’s life has shattered those who loved him. On behalf of my office, I extend my condolences and prayers to Charlie’s wife, Erica, his family, and his friends.”Gray formally charged Robinson with aggravated murder, a capital offence, alleging that Robinson intentionally killed Kirk “under circumstances that created a great risk of death to others.” .'WE GOT HIM': Charlie Kirk assassination suspect is 22-year-old Tyler Robinson, father turns him in.He further alleges Robinson targeted Kirk because of his political expression, and that the shooting occurred in the presence of children who witnessed the violence.Additional charges include felony discharge of a firearm causing bodily harm (first-degree felony). Two counts of obstruction of justice for allegedly concealing evidence and disposing of clothing from the shooting. Two counts of tampering for instructing his roommate to delete incriminating texts and to remain silent if questioned by police and commission of a violent offence in the presence of a child (Class A misdemeanour).Grey stated Robinson went to the Washington County Sheriff’s Office with his parents and a family friend to turn himself in on Sept. 11 — the day after the shooting — after his mother saw a photo of the suspected shooter on the news and believed it resembled her son. She showed it to her husband and he agreed. Robinson’s mother said over the past year Robinson had become more politically active and had shifted left, expressing strong support for gay and transgender rights. She said Robinson began dating his roommate, Lance Twiggs, who is a biological male undergoing a gender transition which led to arguments between Robinson and his father who holds sharply different political viewsThe mother said she later spoke with her son by phone and that he suggested he intended to take his own life. His parents persuaded him to come to their home, where, she said, Robinson implied that he was the shooter and told them he could not go to jail and “just wanted to end it.” When asked why, Robinson allegedly replied that there was “too much evil” and that Charlie Kirk “spreads too much hate,” the mother said..UPDATED: Charlie Kirk assassinated at Utah university.The rifle used in the shooting was Robinson's grandfather's which was given to him as a gift.According to a transcript obtained by law enforcement, Robinson and Twiggs exchanged messages about the shooting and the rifle.Robinson messaged Twiggs, saying, “drop what you’re doing. Look under my keyboard”. Under the keyboard, Twiggs found a note that said “I had the opportunity to take out Charlie Kirk, and I’m going to take it."Robinson then said he was still in the town of Orem, and was trying to retrieve the rifle from the crime scene.“You weren’t the one who did it right????” Twiggs asked.“I am, I’m sorry,” Robinson replied.Robinson said he had been planning the attack for a “bit over a week”.When asked why he did it, he replied: “I had enough of his hatred. Some hate can’t be negotiated out.”Robinson said he had already taken steps to avoid leaving evidence. He described changing clothes and worrying about fingerprints on the weapon, and said the rifle had been wrapped in a towel.Robinson told Twiggs he had considered retrieving the rifle from its hiding place but feared being seen and worried about how he would explain it to his father and grandfather.Robinson said he was also worried that campus security or police had already swept the area.He mentioned concerns about the scope and other identifying features of the rifle — including that the weapon was distinctive and that federal authorities had released a photo — and told Twiggs to delete their conversation.Robinson also commented that since the 2016 election his father had become “pretty diehard MAGA,” according to the transcript.Robinson will remain in custody without bail at the Utah County Jail.