The grandmother of Charlie Kirk’s alleged assassin has claimed the FBI ‘have the wrong man’.

On Wednesday (September 10), the right-wing activist was shot and killed while attending an event at Utah Valley University.

While the FBI launched a widespread manhunt for Kirk’s killer, who they believe acted alone and fired a single bullet from a nearby rooftop of the college campus, it wasn’t long until the authorities announced they had their leading suspect.

Today (September 12), the FBI confirmed they had detained 22-year-old Tyler Robinson in custody.

While standing accused of assassinating Kirk, the alleged suspect’s heartbroken grandmother has reportedly spoken out, claiming they have ‘got the wrong man’ in a case of ‘mistaken identity’.

Speaking to the Daily Mail, Debbie Robinson described him as a quiet, studious young man who ‘never’ spoke about politics, despite his staunch Republican roots.

Charlie Kirk was shot dead on the college campus on Wednesday (Trent Nelson/The Salt Lake Tribune/Getty Images)

The 60-year-old said her son, Robinson’s father, is an avid supporter of President Donald Trump.

“[Tyler] is the shyest person,” she told the outlet. “He has never, ever spoke politics to me at all.

“Most of my family members are Republican. I don’t know any single one who’s a Democrat. I’m just so confused.”

Cops confirmed Robinson was apprehended in custody following a tip-off from a family member.

Tyler Robinson has been named as the suspect (Facebook)

Debbie added that she hasn’t heard from her son since learning about her grandson’s alleged involvement in Kirk’s assassination.

She doubled-down that there is ‘no way’ Robinson could be involved, adding that she believed he hasn’t ever handled such a weapon as the bolt action rifle that killed Kirk, let alone with such precision.

“I don’t think he ever shot a gun, to tell you the truth,” she said.

“He doesn’t hunt, he’s never liked anything like that. I know he doesn’t own any guns.”

Robinson has been apprehended today (FBI)

Debbie continued: “There’s just no way he could have been that good of a shot.”

Gushing praise for her grandson further, she said: “He’s a wonderful child.

“There is no way that he could have done anything like that. I would cross my heart and promise that there was absolutely no way. He has never, ever gotten in trouble in his life. He’s just a very shy, good kid.”

“There’s no way he could be violent,” Debbie claimed. “There’s absolutely no way that he done that.”

His grandmother is adamant he couldn’t have been the shooter (Facebook)

His grandmother’s insight comes as Robinson reportedly had expressed he opposed the views of the conservative activist previously to his family and had become ‘more political’ in the run-up to the shooting, Utah Governor Spencer Cox said.

Still, despite her determination that the FBI has ‘got it wrong’, Debbie did state she was ‘very sad’ for Kirk’s wife and children.

Robinson was arrested at around 11pm local time in southern Utah on Thursday (September 11) evening from his Washington home.

Officials have yet to give a possible motive. If convicted, Robinson could face the death penalty.