The bullet which killed Charlie Kirk did not match his alleged assassin's rifle, court documents have claimed.
Defence lawyers for suspect Tyler Robinson have said federal firearms experts could not link the bullet recovered from Charlie Kirk's body to the rifle allegedly used by their client.
Robinson, 22, faces capital murder charges and a possible death sentence for shooting the conservative activist at Utah Valley University last September.
According to court documents filed on Friday, the Bureau of Alcohol, Tobacco, Firearms and Explosives "was unable to identify the bullet recovered at autopsy to the rifle allegedly tied to Mr Robinson".
The defence team intends to present this ATF analyst testimony as evidence supporting Robinson's innocence.
Prosecutors identified the gun recovered from the crime scene as a Mauser model 98 which had belonged to Robinson's grandfather.
The original Mausers were built to fire eight-millimetre cartridges, but the recovered gun was a .30-06 calibre rifle.
News of the failed match sparked wild speculation online - which was quickly shut down by gun enthusiasts.
One, Zack Bonfilio, pointed out that soft point rounds like those used in a .30-06 rifle are difficult to be matched because they are designed to expand and fragment upon contact with their target.
The bullet which killed Charlie Kirk did not match his alleged assassin's rifle, lawyers said
| GETTYThe defence has requested a delay of at least six months before the preliminary hearing proceeds.
Court filings indicate that DNA analysis from the FBI and ATF revealed genetic material from multiple individuals on certain evidence items.
Lawyers stated that evaluating these findings requires consultation with forensic biologists, geneticists, system engineers and statisticians.
Prosecutors have provided roughly 20,000 electronic files including audio recordings, videos and written documents.
CHARLIE KIRK - READ MORE:
Prosecutors have provided tens of thousands of files including audio recordings, videos and written documents against Tyler Robinson
| REUTERS"The defence team has devoted, and will continue to devote, significant resources, to processing discovery," the motion states.
Attorneys added that the comprehensive review needed to identify missing materials will require hundreds of hours of work.
Robinson was handed over to authorities by his father, Matt, who spotted the family rifle in police photographs released during the search for Mr Kirk's killer.
Text messages allegedly exchanged between Robinson and his roommate Lance Twiggs show the accused discussing the rifle he left behind.
"If I am able to grab my rifle unseen, I will have left no evidence," Robinson allegedly wrote.
Text messages allegedly exchanged between Robinson and his roommate Lance Twiggs (right) show the accused discussing the rifle he left behind
| REUTERS/TIKTOK"Only thing I left was the rifle wrapped in a towel," the message said.
After Kirk's death, Robinson allegedly confessed to his father, who then contacted police.
Robinson returns to court on April 17 for a hearing on whether cameras and microphones should be allowed in the courtroom.
Mr Kirk's widow, Erika Kirk, has advocated for full transparency, saying: "We deserve to have cameras in there."
His lawyers have previously highlighted that publicity over the case before the trial went as far as the White House, with Donald Trump stating after the arrest that he hopes "he gets the death penalty."
The defence plans to present evidence of what they describe as harmful and prejudicial media coverage.