But Deputy Utah County Attorney Sam Pead argued that Grunwald's bail should not be reduced "by even one cent."
In an attempt to show that the teen played an active role in the fatal shootings, Pead detailed the allegations in the case that Grunwald drove her truck on Jan. 30 while her boyfriend, 27-year-old Jose Angel Garcia-Jauregui, fired out the back window while Grunwald stared straight forward, shaking her head slightly at one point.
She was willing to do whatever it took "to ultimately be with her boyfriend in Mexico," Pead told the judge.
Grunwald, who is being held at the Salt Lake County jail, is charged as an adult with aggravated murder, a first-degree felony, and 13 other charges related to the crime spree.
Life in prison without parole is the maximum penalty the teen could face if convicted of aggravated murder. Because she is a minor, she is not eligible for the death penalty.
Grunwald also is charged with two counts of discharge of a firearm, two counts of attempted aggravated murder, and aggravated robbery all first-degree felonies along with charges of felony obstructing justice, failure to respond to an officer, possession or use of a controlled substance and lesser charges of felony discharge of a firearm, and misdemeanor criminal mischief and violation of operator duties after an accident.
Pead told the judge Monday morning that after Utah County sheriff's Sgt. Cory Wride was shot and killed, the couple made a number of phone calls, one to Garcia-Jauregui's uncle.
"They told him that they had done something very bad and needed help getting to California," Pead said, adding that prosecutors also obtained text messages from the teen in which she allegedly details "using meth" and "shooting guns."
But Zabriskie argued that prosecutors were relying on assumptions and allegations, and that no one besides Grunwald truly knows what happened inside her truck on Jan. 30.
"She is as much of a victim in this case as anyone else," he argued. "She was totally intimidated by [Garcia-Jauregui.]"
Ultimately, McDade ruled that her bail should not be reduced, saying he had a responsibility to protect the public.
Grunwald will be back in court on April 16 for a two-day preliminary hearing. At that hearing, a judge will hear evidence in the case and decide whether there is probable cause for the teen to stand trial on the charges.
After the hearing, Wride's brother-in-law, Johnny Revill, said he supports the judge's decision to not reduce Grunwald's bail.
"I think she's where she needs to be," Revill said. "I think she's a possible risk to the innocent community."
Garcia-Jauregui died at a hospital Jan. 31, the day after Juab County deputies ended the shooting spree by shooting and wounding him in the head.
Events began in Utah County at 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 pulled-over Toyota Tundra pickup truck driven by Grunwald.
Wride was sitting in his patrol car checking information given to him by Grunwald and Garcia-Jauregui when Garcia-Jauregui opened the back sliding window of the truck and shot and killed the officer. The girl then sped away from the scene, according to court documents, which rely on dash cam footage from Wride's vehicle.
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, where the truck's tires were spiked. They 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.
According to charging documents, Grunwald and Garcia-Jauregui had been living together for several months at the teen's mother's home in Draper, and the couple planned to wed when Grunwald turned 18 in August.
The girl's grandmother, Renate Grunwald, told The Salt Lake Tribune that her granddaughter met Garcia-Jauregui six months before the fatal shooting while both were working at a meat packaging plant in Draper.
Renate Grunwald said when Garcia-Jauregui moved into Grunwald's home, it set off a conflict between her parents, Jerry Grunwald and Tori Grunwald. Jerry who is Renate's son wanted Garcia-Jauregui out of the house but, according to Renate, Tori wanted to let him stay.
Garcia-Jauregui was paroled in December 2012 from the Utah State Prison after serving five years of a one-to-15-year sentence for 2008 convictions for attempted murder and aggravated assault.