Investigators have released photographs and video footage of suspect, are calling on the public to help identify him.

More than 30 hours after a fatal shooting that has shaken the United States, the federal manhunt for US conservative activist Charlie Kirk’s killer is intensifying.

Kirk, the 31-year-old author and podcast host who helped to revitalise the conservative youth vote and return US President Donald Trump to the White House, died shortly after being rushed to hospital on Wednesday with a gunshot wound to his neck.

On Thursday, authorities released photographs and video footage showing a “person of interest” racing across a university rooftop from which the fatal shot is believed to have been fired. The suspect has not yet been identified.

Here is what we know about the latest in the investigation and Kirk’s killing:

What do we know about where the killer is now?

The suspect, who fatally wounded Kirk with a single gunshot while he was speaking to a crowd of more than 3,000 people at an event at Utah Valley University (UVU) on Wednesday, remains at large. Authorities have also not speculated about any motive behind the shooting.

Police and federal investigators have asked the public to help identify the suspect. Video footage and images of the man have been circulated.

Utah Governor Spencer Cox said investigators had completed more than 200 interviews and asked the public to keep sending photos and videos to the Federal Bureau of Investigation (FBI). He added that investigators had received about 7,000 tips from the general public.

“We need as much help as we can possibly get,” he told a news conference on Thursday night, alongside FBI director Kash Patel and his deputy, Dan Bongino. “We cannot do our job without the public’s help right now.”

Authorities also said they found a palm print on the rooftop, a shoe impression and a hunting rifle in nearby woods where it is believed that the attacker fled.

What details have been released about the suspect?

Utah’s Department of Public Safety released several photographs of a white man wearing Converse trainers, jeans, a long-sleeved black T-shirt with a US flag and eagle on it, and a black baseball cap with a triangle.

Surveillance footage released at the news conference shows the man fleeing across a university rooftop about 120 metres (400ft) from where Kirk was speaking, before dropping down to the ground and running along the edge of the campus car park, across the road and into nearby woods, leaving behind palm and shoe prints which are now being analysed.

What do we know about the weapon used to kill Kirk?

Investigators said they had recovered a bolt-action rifle in the nearby woodland, which they believe to have been used in the shooting.

FBI special agent Robert Bohls described the weapon as “a high-powered, bolt-action rifle”. According to US media outlets citing sources, it is an imported Mauser .30-06 bolt-action rifle.

Unlike semi-automatic guns, bolt-action rifles have a slower rate of fire but are valued for their precision. Bohls said the weapon is currently undergoing analysis at an FBI laboratory for possible evidence.

The rifle and three unfired rounds of ammunition inside it were reported to be engraved with expressions of transgender and antifascist ideology, the Wall Street Journal said on Thursday, quoting a person familiar with the investigation and an internal law enforcement bulletin.

What else are investigators doing to find the shooter?

On Thursday, the FBI announced a reward of up to $100,000 for information leading to the identification and arrest of the person, or people, responsible for the fatal shooting of Kirk.

Utah’s governor, Spencer Cox, who has pledged to pursue the death penalty when the attacker is found and tried, said the FBI has so far received 7,000 tips and leads.