WESTMINSTER, Colo. (KKTV) – UPDATE (1/7/19):
A judge has entered a not guilty plea on behalf of a man accused of killing a 13-year-old and wounding three other people in a shooting prosecutors say was motivated by road rage.
A judge denied a request by Jeremy Webster's attorneys for more time to enter a plea on Monday. KUSA-TV reports that a trial is set to begin June 12.
Authorities have said Webster followed the boy's mother, 41-year-old Meghan Bigelow, into a Westminster parking lot on June 14 after a traffic incident. Witnesses told police Webster opened fire, killing 13-year-old Vaughn Bigelow.
The boy's mother and eight-year-old brother, Asa, were seriously injured but recovered. An adult man also was shot.
Webster's attorneys have indicated the 23-year-old was being treated for mental health issues, including bipolar disorder.
PREVIOUS STORY (6/15/18 4:30 p.m.): A search warrant and arrest papers obtained by CBS for the Westminster shooting provide more details on what led up to Thursday's deadly scene.
Witnesses told authorities they saw the suspect, identified as 23-year-old Jeremy Webster, park his car behind a vehicle driven by 41-year-old Meghan Bigelow just after 3 p.m.
Witnesses went on to describe what unfolded soon after Webster and Bigelow started arguing with Bigelow's three children nearby. While arguing, Webster reportedly pulled out a handgun and shot Bigelow several times.
Witnesses say Webster then allegedly turned to two of Bigelow's children and shot each of the kids multiple times. The third child ran away to safety. After one of the children fell to the ground, witnesses told police Webster walked up to him and shot him again.
The arrest papers go on to say, Webster, "appeared to make eye contact" with a bystander identified as John Gale who was sitting in his truck in the parking lot with his 9-year-old daughter. Webster reportedly walked toward Gale's truck and fired multiple rounds hitting Gale in the arm. Gale was able to put his truck into reverse and sped out of the parking lot. His 9-year-old daughter was not injured.
The child who escaped without physical injury told police his mother and Webster were involved in some type of road rage incident prior to the shooting. The child said Webster followed his mom to the parking lot. Before getting out of the car, Bigelow's child said his mom took a picture of Webster's license plate. The child witnessed his mom and siblings get shot.
Detectives were able to find the picture from Bigelow's phone and shared the license plate number with the public. Webster was eventually arrested when his car was spotted hours later along I-25 in Castle Rock.
As more information becomes available this article will be updated.
Click here to read the full arrest papers.
UPDATE (6/15, 2:10 p.m.): A search warrant tied to the Thursday's Westminster shooting state the suspect told police he has mental health issues, but the document didn't provide specifics.
Jeremy Webster, 23, is suspected of shooting and killing a boy, critically injuring that boy's mother and brother along with injuring a fourth adult male bystander.
Webster was arrested along I-25 in Castle Rock hours after the shooting. According to records, Webster has an address listed in Colorado Springs.
Officers say they believe the shooting stemmed from a road rage incident and that the suspect did not know any of the victims.
Officers first responded to the shooting just after 3 p.m. on Thursday in the parking lot of a dental office at 80th Avenue and Sheridan Boulevard.
The investigation is still ongoing.