FBI has released new image of person of interest in connection with Charlie Kirk's assassination

The FBI has released new images of the man they believe to be behind the brutal assassination of right-wing activist Charlie Kirk.

The 31-year-old was fatally shot during an appearance at a rally on Utah Valley University's campus, where he'd planned on debating with students in the open air venue.

Seconds after being asked a question from an attendee about gun violence, however, the Turning Point USA founder was struck by a gunman who fired a single bullet through his neck.

Three thousand onlookers watched in horror as Kirk could be seen recoiling in his chair and falling to the ground.

His death was later confirmed by political ally Donald Trump, who wrote on Truth Social: "The Great, and even Legendary, Charlie Kirk, is dead. No one understood or had the Heart of the Youth in the United States of America better than Charlie.

Kirk was fatally shot during a rally (Trent Nelson/The Salt Lake Tribune/Getty Images)

"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!"

The new images in question show a man walking up a staircase, wearing a pair of sunglasses, cap and a black long-sleeved t-shirt.

The latest update comes just hours after police first gave details about a possible suspect, revealing him to be of 'college age'.

Earlier today, Beau Mason, the commissioner of the Utah Department of Public Safety, said in a press update: "We were able to track the movements of the shooter starting at 11:52 am. This subject arrived on campus shortly away from campus.

"We have tracked his movements onto the campus through the stairwells, up to the roof, across the roof, to a shooting location."

Mason added: "After the shooting, we were able to track his movements as he moved to the other side of the building, jumped off of the building and fled, off of the campus and into a neighbourhood."

The FBI has released an image of the person of interest (FBI)

FBI agent Robert Bohls also joined Mason in the press conference, confirming that they'd located the gun that believe was used to kill Kirk.

He said: "I can tell you that we have recovered what we believe is the weapon to be that was used in yesterday's shooting is a high powered bolt action rifle.

"That rifle was was recovered in a wooded area where the shooter had fled. The FBI laboratory will be analysing this weapon."

Of the possible suspect, Mason claimed the man 'blended in well with the college institution'.

He added, however, that officials were reluctant to release 'many details right now'.

"We will soon. But right now, we're not," Mason assured.

Police in the area previously authorised door-to-door checks in residential areas surrounding the campus still underway as part of their hunt for Kirk's killer - whose motives remain unknown as of yet.

Images of a person of interest have been released (FBI)

It was subsequently theorised that a dark figure had been situated upon a roof of Utah Valley University, around 142m from the gazebo in which the conservative was sitting.

Two individuals were arrested on the scene, but were later released, with police finding 'no current ties' to the victim.

A representative of the Department of Public Safety previously claimed it's working at 'multiple active crime scenes', which could describe from where Kirk was shot, 'as well as the locations where the suspect and victim travelled'.