LOS ANGELES, United States (AFP) — The man accused of murdering influential right-wing campaigner Charlie Kirk broke down in tears of regret days after the killing, according to video testimony played in a United States (US) court on Thursday.

The development came on the fourth day of a hearing to determine if there is enough evidence to try 23-year-old Tyler Robinson for the university campus assassination of the influential Kirk, a supporter of Donald Trump who was credited with mobilising a huge youth vote for the 80-year-old Republican president.

“I just asked him in person if what he said was true the night before, and he said it was,” Robinson’s roommate Lance Twiggs told investigators in the taped interview.

“He started crying a little bit, and said he wishes he hadn’t done it.”

Robinson, who was raised a Republican, faces the death penalty if he is found guilty of shooting Kirk on a Utah campus last September, in a crime that sent shock waves through the United States, and roiled right-wing politics.

Investigators earlier revealed that Robinson had confessed to the murder via text messages to Twiggs, in which he indicated he was fed up with the “hatred” Kirk spread.

His relationship with Twiggs has been the subject of fascination in the US, where the case is being closely followed.

Twiggs, who is transitioning to become a woman, was not merely a roommate but was also in a romantic relationship with Robinson, with fevered online speculation that this may have provided a motive for the murder of Kirk, a Christian nationalist who was highly critical of the LGBT community and transgender people.

Speaking to investigators, Twiggs acknowledged that Robinson sometimes discussed politics.

“He usually talked about stuff he heard on the radio on his drive to work,” the witness recounted. But prior to the murder, “I personally had never heard him talk about Charlie Kirk before specifically.”

Twiggs also said the couple had “not really” discussed the situation of transgender people and the LGBT community in the United States.

They first met in 2023 — initially just as roommates — before beginning a romantic relationship “two or three months” after Robinson moved in, Twiggs told investigators.

Robinson has not yet indicated how he intends to plead.

This current set of proceedings, in Utah, is expected to finish on Friday.