Clarken, who was returning to his Salt Lake City home from Las Vegas that day, said he was several feet away when he saw police gun down 27-year-old Jose Angel Garcia-Jauregui and arrest both him and Grunwald.
"She was so distraught that he had been shot," said Clarken, recalling the girl's reaction. "She was sobbing uncontrollably. ... She was just freaking out, telling police, 'You f-ing assholes, you didn't have to f-ing kill him!' "
Freeway gunplay • Initially, Clarken said he had no idea what was unfolding in front of him just south of Nephi, with his wife and 10-year-old son in the car. When he saw Utah Highway Patrol lights flash behind him, he thought he was being pulled over for speeding.
Then, he saw a UHP trooper suddenly pull out of the median in front of him. Clarken said he braked suddenly to avoid hitting the trooper, and eventually came to a complete stop as he saw people running on the highway and the shooting unfold before him.
In that moment, Clarken said he wasn't sure if the men dressed in what he thought looked like snowmobile suits were police or what exactly he had just run into.
"They don't look like police officers," he recalled. "They look like hunters."
In fact, Clarken who said he has a concealed carry gun permit had pulled out his own gun in case he needed to protect himself from whatever was going on.
"We were 10 feet from where [Grunwald] was," he said. "That's why I got my 45 [caliber gun]. I don't know who this crazy person is. She was coming closer and closer to the car."
But before Grunwald could get any closer to his vehicle, Clarken said police fired off rounds at Garcia-Jauregui, who was struck by a bullet in the top of his head. He died the next day at a local hospital.
As police were arresting the couple, Clarken said he heard an officer yell to him to get out of the area, so they drove away, still not knowing what just happened or why.
"I thought that guy did something," Clarken said about the man police shot. "By the number of cops, [I thought] that guy killed a cop. Either a child or a police officer."
Witness: "I feel lucky" • But it wasn't until the family arrived home and saw media reports that they discovered exactly what had happened. After they learned Grunwald and Garcia-Jauregui had carjacked someone and had been shooting at random at passing vehicles, Clarken said he was grateful he wasn't in the area minutes earlier, putting his family at risk.
"Just lucky, you know?" he said of his feelings after the event. "I feel lucky we weren't there."
For months afterward, Clarken said he didn't really talk about the incident, and didn't volunteer information to police or prosecutors. He was trying to protect his son, he said, because he did not want the young boy to have to rehash the graphic details to law enforcement.
But after seeing media reports where Grunwald's attorney told reporters that Grunwald would take the stand in her own defense at trial and say she was in fear for her life, Clarken said he felt he needed to come forward.
"Her choices were reduced to either comply or give up her own life," defense attorney Dean Zabriskie told news reporters following a preliminary hearing earlier this month.
Clarken said he felt that any claim that the girl was being held against her will by Garcia-Jauregui was "absolute bulls-t" compared to what he saw.
"She was very distraught that he had been killed," Clarken said. "If I was being held against my will, I'm not going to shed a single tear [for the captor.] That didn't wash with me at all."
Grunwald is charged as an adult in Provo's 4th District Court with aggravated murder in the death of Utah County Sgt. Cory Wride on a road near Lehi, and attempted aggravated murder for the wounding of Utah County Sheriff's Deputy Greg Sherwood in Santaquin.
She also is charged with two counts of attempted aggravated murder, three counts of criminal mischief, aggravated robbery, failure to respond to an officer, possession or use of a controlled substance and violation of operator duties after an accident.
Grunwald was ordered to stand trial on the charges following the preliminary hearing. She is expected to be in court again for an arraignment on May 12.
Grunwald at the wheel • The deadly crime spree began about 1 p.m. on Jan. 30, when Wride stopped his patrol car on State Road 73 about 5 miles west of Lehi to check on a Toyota Tundra pickup truck that was stopped on the shoulder.
Wride was sitting in his patrol car checking information given to him by Grunwald, who was allegedly driving, and Garcia-Jauregui, when the man allegedly opened the back sliding window of the truck and began shooting at the officer.
Seven shots were fired toward Wride, according to police investigators. The first two struck the windshield, and killed Wride.
Police believe Grunwald was still driving the truck when she encountered Utah County Sheriff's Deputy Greg Sherwood in Santaquin.
As Sherwood was following the truck in his patrol vehicle, prosecutors allege the teen girl braked suddenly closing distance between her truck and Sherwood's vehicle and Garcia-Jauregui fired from the back window of the truck once more. Sherwood was struck once in the head.
The two continued south on Interstate 15, with Garcia-Jauregui taking shots at random vehicles, including a semi-truck, according to preliminary hearing testimony.
After police spiked the Tundra's tires, the pair commandeered another vehicle at gunpoint, but that vehicle was disabled by tire spikes south of Nephi, where Juab County sheriff's deputies arrested them after shooting and wounding Garcia-Jauregui, according to court documents.