Kirk, a close ally of Trump, was assassinated while speaking at a university campus in the US state of Utah last week. The alleged gunman, Tyler Robinson, has been taken into custody , charged with aggravated murder and six other offences, including obstruction of justice and witness tampering. Prosecutors have said they will seek the death penalty. Kirk co-founded Turning Point USA, which is the largest conservative youth organisation in the country. According to a program and website from the group, called Fight for Charlie, the memorial will be held from 11am on Sunday local time (4am on Monday AEST). It will take place at State Farm Stadium in Arizona, which is the home of the National Football League's Arizona Cardinals. The stadium has a fixed capacity of 63,400 which is expandable to over 73,000 for larger events. Entry to the event will operate on a first-come, first-served basis. The website says “enhanced security measures” will be in place, and guests arriving with bags will not be permitted entry. According to local reports, Secret Service spokesperson Anthony Guglielmi said in a statement earlier this week that “joint security planning is underway” for the memorial and “appropriate public safety related information” would be provided in the coming days. Attendees are being asked to wear red, white or blue. The website details a list of those who are expected to deliver remarks, including Trump, vice president JD Vance, and Kirk's widow, Erika Kirk. Also among those included in the list are White House chief of staff Susie Wiles, US secretary of state Marco Rubio, health secretary Robert F Kennedy Jr, defence secretary Pete Hegseth, national intelligence director Tulsi Gabbard, Trump's son Donald Trump Jr and conservative talk show host Tucker Carlson. When asked by journalists whether he would be attending, Trump reportedly said on 11 September: “I will be.” “They've asked me to go, and I think I have an obligation to do that.” download our app subscribe to our newsletter