We continue our coverage of an Odessa brother and sister who are both accused in the murder of their parents.

On Tuesday, 22-year-old Grace McDonald was arrested by U.S. Marshals in Arizona on capital murder and criminal conspiracy charges.

This comes four months after her 17-year-old brother, Gabe McDonald was indicted for the same crime.

CBS 7 News obtained a copy of Grace's indictment Wednesday morning.

Although the indictment doesn't go into detail on what evidence was presented to the grand jury, it does state that Grace agreed with Gabe that one of them would shoot and kill their parents.

"There's no perfect family, but if you were to even look at a family and say, man that's the perfect family, they were it," said long-time friend Evan Rogers.

This is how friends and family remember the McDonald family -- Gregg, Jana, Grace and Gabe.

When news broke on March 2, 2016 that Gabe allegedly shot and killed his parents as they slept, many in the community were at a loss for words.

Now six months later, another shocking development -- investigators say Grace assisted her brother in killing their parents.

Reaction on social media from people who know Grace indicate a strong circle of support.

One friend on Facebook writes, "Me and Grace are good friends and I've never seen evilness of her."

Another says, "She's such a sweet heart, especially growing up, her parents were so involved with them."

Bland wouldn't tell us when their investigation into Grace’s involvement began, but he did say they presented evidence to the grand jury on Monday.

"From day one we always worked with police to make sure the evidence was examined, that if anything developed we'd follow that up and that's what we did in this case," Bland explained.

While Bland isn't saying she pulled the trigger, he says she did take part in planning her parent’s deaths. In Texas, if Grace is convicted of capital murder she will be charged as if she was the one behind the gun.

"This does not change the charges against James Gabriel McDonald,” said Bland. “He is still charged with the crime of capital murder and it didn't change the evidence against him."

Bond is set for both Gabe and Grace at $2 million each.

Bland says the next step is to have Grace extradited back to Ector County from Arizona.

According to Gabe’s attorney, Justin Low, Grace was receiving some sort of medical treatment out there.

We also had a chance to speak with the siblings’ grandmother, who doesn't believe Grace had any part in this murder.

She says she supports both of her grandchildren 100 percent and is still trying to wrap her head around this latest news.

Bland tells us he will not seek the death penalty for Grace McDonald, and because of his age, Gabe will not be facing the death penalty either.