The adult suspect in the STEM School Highlands Ranch shooting that left one dead and eight more injured will not face the death penalty if convicted, according to court documents filed the morning of March 5.

The family of slain STEM senior Kendrick Castillo urged the death penalty.

Eighteenth Judicial District Attorney George Brauchler said in the filing he decided against pursuing the death penalty for Devon Erickson, 19, after numerous in-person and phone conversations with John and Maria Castillo, Kendrick's parents.

“The Castillo family is unequivocal that it is their genuine desire that capital punishment be sought for the defendant,” Brauchler wrote. “It is my solemn obligation to ensure that their position is heard and understood through this pleading.”

But Brauchler noted jurors would be asked to weigh the suspect's age and lack of serious prior convictions in deciding on the death penalty.

Erickson is accused of helping Alec McKinney, 16, organize and carry out the May 7 attack at STEM. Castillo, 18, died while rushing Erickson with two other students at the onset of the shooting, according to authorities.

Erickson goes to trial in May and faces 44 felony charges, including first-degree murder. He pleaded not guilty in January.

McKinney accepted a plea agreement in early February. He will be sentenced on May 18 for counts including first-degree murder and also will not face the death penalty.

Under state law there are 17 aggravating factors that can trigger pursuing capital punishment in a case. At least one must be proven beyond a reasonable doubt to a jury for the death penalty to be considered.

Brauchler outlined several potential aggravating factors that appear in the STEM case.

Those are, where the possession of the weapon used to commit the crime constitutes a felony offense; the perpetrator creates a grave risk of death to another in addition to the victim who was killed; the commission of a class 1, 2, or 3 felony that also results in someone's death; an agreement to kill; and killing from ambush.

In weighing those aggravating factors, a jury would also be asked to consider Erickson's age, the absence of significant prior convictions and additional evidence. Erickson was 18 at the time of the shooting.

“We were for the death penalty," John Castillo said. "We feel that there's at least six aggravators there that would make it possible."

John Castillo said in his conversations with prosecutors, the district attorney expressed doubt that they could successfully seek the death penalty. The district attorney anticipated defense attorneys would rely on Erickson's cocaine use before the shooting, which the suspect alleges he was forced to consume, and his lack of serious prior convictions, John Castillo said.

Brauchler was not available for comment on March 5. A spokeswoman said the district attorney's office does not comment on open cases.

The family knows death penalty cases can be “a long shot,” John Castillo said, pointing to the Aurora theater shooting and a jury's decision against the death penalty for convicted killer James Holmes. Holmes, who killed 12 people in the attack, was sentenced in 2015 to life in prison after jurors failed to unanimously agree to hand him the death penalty. Brauchler also prosecuted that case.

Still, the Castillos believe the death penalty is “deserved in this case,” John said.

“Justice for Kendrick would mean them having to sacrifice and give up their life," John Castillo said. "It's just that plain and simple. That's how my wife and I feel."

McKinney will face a minimum sentence of life with the possibility of parole after 40 years and a maximum sentence of life with the possibility of parole after 40 years, plus 409 years in the department of corrections.

In February, Brauchler told reporters that McKinney could be eligible for a juvenile program in the Department of Corrections that paroles him in 20 to 25 years.

The death penalty has been a hot-button issue in Colorado this year.

State lawmakers repealed the death penalty on Feb. 26. Colorado will be the 22^nd state to abolish the death penalty once Gov. Jared Polis signs the bill into law, which he has pledged to do.

The law would only apply to crimes charged on or after July 1, which would have meant Erickson was eligible for the death penalty.

John Castillo said he felt repealing the death penalty in Colorado should have been sent to the voters and he was disappointed to see lawmakers decide for them. He also understands some people will disagree with the family's stance on capital punishment.

“I think most people would have to be where my wife and I are to understand,” he said.