The 23-year-old Robinson is charged with aggravated murder in the Sept. 10 assassination of Kirk on the Utah Valley University campus. Prosecutors are seeking the death penalty.
Kirk killing suspect said 'he wishes he hadn't done it' in video
Robinson's lawyers plan to call a final witness as they try to raise doubts about the prosecution's case. The defense has previously challenged the reliability of ballistics tests on a bullet fragment recovered from Kirk's body and fought the release of a recorded interview with Robinson's roommate, Lance Twiggs, as well as chat room messages Robinson wrote on Discord.
There are only 14 seats for the public in the courtroom
People have been lining up early - sometimes sleeping outside the doors overnight - in hopes of getting a wristband for a seat in the courthouse this week. Only 14 wristbands are given out each day, on a first-come, first-served basis.
Chris Palmer, the court's director of security, warned Thursday morning that tents and other camping supplies won't be allowed as people seek a seat for the final day of the hearing Friday. He also warned against jumping in line or saving spots for someone else.
Earlier in the week, court security said it discovered some people had bought colored wristbands to try to sneak in.
Defense tries to sow doubt about ballistics evidence
One of Tyler Robinson's attorneys, Michael Burt, tried to inject doubt into the prosecution's case by challenging the reliability of ballistics tests on a bullet fragment recovered from Kirk's body.
Authorities sought to tie the fragment to the suspected murder weapon, but the results were inconclusive.
"Saying anything but inconclusive was inappropriate," said Samantha Karner with the Bureau of Alcohol, Tobacco, Firearms and Explosives.
The defense earlier in the week had questioned the reliability of DNA evidence that investigators said linked Robinson to the scene. Experts say the science behind DNA testing is sound.
Robinson's attorneys plan to have a second person from ATF testify Friday.
The prosecution ended its presentation Thursday afternoon.
Testimony in five-day preliminary hearing wraps Friday
After testimony in the preliminary hearing ends Friday, State District Judge Tony Graf will rule whether prosecutors have shown enough evidence to proceed to trial. But a decision from Graf won't come immediately.
Attorneys on both sides say they'd like the benefit of seeing the court transcript of the preliminary hearing and want to submit written briefs before Graf weighs in.
That will take weeks to play out. Graf set oral arguments on the evidence presented in the preliminary hearing for Sept. 1.
Graf tends not to make immediate rulings.
The video in the player above is from a previous report.