The FBI is looking into whether people close to Charlie Kirk's assassin had foreknowledge of the horrific murder, as evidence mounts of the killer's connection to the radical left.

While no one else is facing charges at this time, alleged shooter Tyler Robinson told somebody he would murder Kirk over his political beliefs, FBI director Kash Patel said Monday. Patel did not specify who that individual was.

“He had a text message exchange with another individual in which he claimed that he had an opportunity to take out Charlie Kirk — and he was going to do it because of his hatred for what Charlie stood for,” Patel told Fox & Friends.

Did others know?

Patel said the FBI is still looking into why the other person did not report the exchange to police and Patel did not say whether that person will face charges.

Robinson also wrote a note saying he had an opportunity to kill Kirk, Patel said. The note was left inside the home that Robinson shared with a transgender boyfriend, who has been identified as 22-year-old Lance Twiggs.

Twiggs is cooperating with police and has not been accused of any wrongdoing.

A family member told Fox News that they believe Twiggs "hates Christians" and that he may have helped radicalize Robinson, who was raised Mormon.

Twiggs reportedly comes from a conservative Christian family, reports the Daily Mail, and he is part of the "furry" subculture, which is based on a sexual interest in anthropomorphic animals.

From the left

The spent casing from the bullet that killed Kirk had the phrase, "Notices bulge OwO what’s this?” which is a reference to a furry meme. Another bullet casing had a message taunting Kirk as a "fascist."

Kirk was answering a question about the role of transgenders in mass shootings right before he was shot.

People on the left have asserted, without evidence, that Robinson is a Republican. His family members have told investigators that he was becoming very left-wing in recent years, FBI director Patel said.

"His family has said that he subscribed to left-wing ideology, and even more so in these last couple of years," Patel told Fox News.

All we know at this stage is that Robinson is tied to the left, and he appears to have warned people about his murder plot beforehand. Whether anyone else is facing criminal exposure remains to be seen.