Trump pledges to find killer of conservative activist Charlie Kirk

US President Donald Trump vowed retribution for the murder of conservative activist Charlie Kirk on Wednesday as police went door-to-door searching for the suspect.

Kirk — a prominent conservative activist and co-founder of youth organisation Turning Point USA — was shot in front of a crowd of 3,000 people as he spoke about gun violence at a campus event in Utah on Wednesday.

He was answering a question about how many mass shootings there had been in total in the US in the last couple of years before he was struck by a single shot, officials said they believed to be launched from the roof of a building.

He died at the hospital after being rushed away by security, authorities said.

Kirk's death marks a "dark moment for America," Trump said in an Oval Office address. He blamed the "radical left" for several instances of political violence in the US last year, including the assassination attempt on his own life and the killing of United Healthcare CEO Brian Thompson.

“My administration will find each and every one of those who contributed to this atrocity, and to other political violence," Trump said.

“For years those on the radical left have compared wonderful Americans like Charlie to Nazis and the world’s worst mass murderers and criminals. This kind of rhetoric is directly responsible for the terrorism that we’re seeing in our country today and it must stop right now,” he added.

The US president made no mention of instances of violence against Democrats, such as the murder of Minnesota lawmaker Melissa Hortman in June.

Manhunt ongoing

A massive search for the killer intensified following Kirk's death, with police going door-to-door looking for the shooter.

Two suspects have been arrested and released, with FBI Director Kash Patel announcing a suspect in custody released after interrogation was found to have no ties to the shooting. "Our investigation continues and we will continue to release information in interest of transparency," Patel wrote on X.

Utah's Department of Public Safety said the attack was "targeted" with the suspect appearing to have fired the shot from the roof of a building into a courtyard where Kirk was debating with a large crowd below.

“This shooting is still an active investigation,” the department said in a statement, adding local police departments and the FBI.

Politicians from across the political spectrum condemned the incident, which sparked a shouting match between Democrats and Republicans in the US House of Representatives over gun violence.

Republican National Chairman Joe Gruters called the violence "horrifying" and called for "Republicans and Democrats alike must stand united in condemning this brutality that has no place in America.”

Former US Presidents Bill Clinton and Barack Obama expressed condolences, with Obama writing on X: "We don’t yet know what motivated the person who shot and killed Charlie Kirk, but this kind of despicable violence has no place in our democracy."

Former President Joe Biden said, "There is no place in our country for this kind of violence. It must end now."

Israeli Prime Minister Benjamin Netanyahu and UK Foreign Secretary Yvette Cooper also condemned the attack. "I spoke to him only two weeks ago and invited him to Israel. Sadly, that visit will not take place. We lost an incredible human being," Netanyahu said.