The federal investigation into the assassination of conservative activist Charlie Kirk has yet to find a link between the alleged shooter, 22-year-old Tyler Robinson, and left-wing groups on which President Donald Trump and his administration have pledged to crack down after the killing, three sources familiar with the probe told NBC News.

One person familiar with the federal investigation said that “thus far, there is no evidence connecting the suspect with any left-wing groups.”

“Every indication so far is that this was one guy who did one really bad thing because he found Kirk’s ideology personally offensive,” this person continued.