There is no clear, confirmed evidence in the available sources that the suspect in Charlie Kirk's killing was 'radicalized' in college or that he did one semester online at Utah State during COVID.
Kari Lake says Kirk’s killer was “radicalized” in college. He did one semester online during COVID, at Utah State.

First Thing: Kirk shooting suspect had ‘very different ideology’ to conservative family, Utah governor says - US news | The Guardian
Source: theguardian.com
Key Evidence
Utah Governor Spencer Cox described the suspect as having a very different ideology from his family and being radicalized online.
theguardian.comtheguardian.comFirst Thing: Kirk shooting suspect had ‘very different ideology’ to conservative...
timesofisrael.comtimesofisrael.comUtah governor: Charlie Kirk murder suspect 'clearly a leftist,' lived with trans...
The suspect is currently enrolled in an electrical apprenticeship program at Dixie Technical College, not Utah State University.
pbs.orgpbs.orgUtah Gov. Cox shares more details from investigation into motive of Kirk...
No source confirms the suspect attended Utah State University for one semester online during COVID or that his radicalization specifically occurred in college.
What the Evidence Shows
The claim that Kari Lake said Kirk’s killer was 'radicalized' in college and that he did one semester online at Utah State during COVID is not directly supported by the provided sources. Multiple sources report that the suspect, Tyler Robinson, had a very different ideology from his conservative family and was described by Utah Governor Spencer Cox as 'clearly a leftist' who lived with a trans partner.theguardian.comtheguardian.comFirst Thing: Kirk shooting suspect had ‘very different ideology’ to conservative...
timesofisrael.comtimesofisrael.comUtah governor: Charlie Kirk murder suspect 'clearly a leftist,' lived with trans...
The governor also mentioned the suspect was radicalized online, but none of the sources specify that this radicalization occurred during college or that it was linked to a semester at Utah State University. Furthermore, one source states the suspect is currently enrolled in an electrical apprenticeship program at Dixie Technical College, but there is no mention of Utah State University or online study during COVID.pbs.orgpbs.orgUtah Gov. Cox shares more details from investigation into motive of Kirk...
The sources focus more on ideological differences and online radicalization rather than educational history or specific semesters attended. Therefore, the specific details about college radicalization and one semester online at Utah State remain unverified based on these sources.