An analysis from the federal Bureau of Alcohol, Tobacco, Firearms and Explosive (ATF) could not conclusively connect a bullet fragment recovered during Charlie Kirk’s autopsy to the rifle found near the scene of the rightwing political activist’s killing – and the FBI is running additional tests, lawyers for Kirk’s accused murderer said in recent court filings.

In the court filings, Tyler Robinson’s defense team also asked for a delay to a preliminary hearing scheduled in May, saying they need time to review the bullet analysis as well as an enormous amount of other material that could contribute to the suspect’s defense.

The ATF’s bullet analysis report has been kept private, but attorneys have cited snippets in other public filings that say the results were inconclusive.

The defense said in its motion that it may try to use the analysis to clear Robinson of blame during the preliminary hearing while prosecutors aim to show they have enough evidence against him to proceed with a trial.