OREM, Utah (AP) — The FBI released two photos of a person of interest in the assassination of Charlie Kirk, a close ally of President Donald Trump who played an influential role in rallying young Republican voters. The shooter, who fired a single shot from a distant roof, remained at large and unidentified on Thursday nearly 24 hours into the investigation.

The release of photos of a person in a hat, sunglasses and a long-sleeve black shirt, as well as a $100,000 reward for information leading to an arrest, reflected law enforcement’s urgent appeal for public help in locating the gunman, who vanished after jumping off the roof and fleeing through a wooded area near the Utah university where Kirk was killed in a targeted attack.

Investigators were sifting through potential clues, including a palm print and a shoe impression found near the scene, as well as a Mauser .30-caliber bolt-action rifle hidden in a towel in a wooded area near the university campus along what they suspect to be the path the shooter took while fleeing. Besides the spent cartridge recovered in the chamber, three other rounds were loaded in the magazine, according to information circulated among law enforcement and described to The Associated Press. The weapon and ammunition are being forensically analyzed by law enforcement at a federal lab for clues that could help identify the shooter or the motive.

The new information suggested at least modest progress in an investigation into a killing that law enforcement was treating as the latest instance of political violence to convulse the United States across the ideological spectrum. Yet key questions remained unanswered. Law enforcement had yet to identify the shooter or disclose a motive and acknowledged at a news conference Thursday that the suspect’s college-age appearance may have helped the person blend in on the college campus where Kirk was shot.

The Wednesday afternoon attack, carried out in a broad daylight as Kirk spoke about social issues at a Utah Valley University courtyard, was captured on grisly videos circulating on social media. The videos show Kirk speaking into a handheld microphone when suddenly a shot rings out. Kirk can be seen reaching up with his right hand as blood gushes from the left side of his neck. Stunned spectators gasp and scream before people start running away.

Trump, who was joined by Democrats in condemning the violence, said he would award Kirk the Presidential Medal of Freedom, the highest civilian honor in the U.S., while Vice President JD Vance and his wife, Usha, were set to visit with Kirk’s family in Salt Lake City. Vance posted a remembrance on X chronicling their friendship, dating back to initial messages in 2017, through Vance’s Senate run and ultimately praying after hearing of the shooting.

“So much of the success we’ve had in this administration traces directly to Charlie’s ability to organize and convene,” Vance wrote. “He didn’t just help us win in 2024, he helped us staff the entire government.”

Kirk’s casket was to be flown aboard Air Force Two from Utah to Arizona, where his his nonprofit political youth organization, Turning Point USA, is based.

Kirk was taking questions about gun violence