Lindsey Cunningham, sister of Indiana Fever star Sophie Cunningham, voiced outrage after conservative activist Charlie Kirk was shot and killed on stage Wednesday at Utah Valley University.On Instagram, Lindsey shared posts mourning the family Kirk left behind after his death at 31, including reposts from conservative pages.“She lost her husband & those babies lost their father bc some POS (piece of s**t) had differing political views,” she wrote.“Emphasis on POS,” she added, alongside a photo of Kirk holding his newborn. “Sad. Sick. Outraged.”Sophie Cunningham's sister Lindsey Cunningham pens hard-hitting message after Charlie Kirk's murder stuns AmericaUtah Gov. Spencer Cox condemned the shooting as a “political assassination.”“This is a dark day for our state. It’s a tragic day for our nation," he said in a press conference. "I want to be very clear that this is a political assassination.”Kirk, a close ally of former President Donald Trump, was a key figure in energizing young Republican voters. Cunningham’s hometown is Columbia, Missouri, a state Trump carried with 58.49% of the vote and all 10 electoral votes."The Great, and even Legendary, Charlie Kirk, is dead," Trump posted on social media. "No one understood or had the Heart of the Youth in the United States of America better than Charlie. He was loved and admired by ALL, especially me, and now, he is no longer with us. Melania and my Sympathies go out to his beautiful wife Erika, and family. Charlie, we love you!"Before his appearance on campus, an online petition urging administrators to block Kirk from speaking gathered nearly 1,000 signatures, according to the AP.The university responded with a statement citing First Amendment protections, stressing its “commitment to free speech, intellectual inquiry and constructive dialogue.”NBA star Michael Porter Jr. reacts Charlie Kirk's shootingBrooklyn Nets forward Michael Porter Jr. also reacted to Kirk’s killing on Instagram. He first shared disbelief after watching the widely circulated video of Kirk being shot in the neck and collapsing.He then denounced the act and mourned Kirk’s death.“RIP to Charlie SMH…I never watched his stuff but nobody deserves to die like that. Man had a wife and kids…He was killed for sharing his opinions and giving an opportunity to share theirs as well. This is sad man…Praying for the family!”Authorities said two people were arrested in connection with the shooting but later released, according to reports. The gunman remains at large.