The 12-year-old boy was described by friends as a wholesome kid who often volunteered at church, handing out bulletins, working audio and video equipment and helping other kids learn Bible verses.
They said he showed no outward signs of family problems.
Then, police say, the boy did the unthinkable, allegedly killing his parents and wounding two of his younger siblings in a case that has rattled this rural farming and ranching community of 3,700 near the Kansas border.
Police say they discovered the attacks Tuesday after the boy called 911 to report a shooting.
When officers arrived, they found the bodies Charles and Marilyn Long, who had been fatally shot. Two of the couple's children _ a 5-year-old girl and a 9-year-old boy _ were wounded.
The 12-year-old boy was then taken into custody, stunning friends and neighbors.
District attorney Robert Watson said Thursday he plans to file two counts of first-degree murder and other charges against him by the end of Friday. He hasn't decided whether to try to prosecute the boy as an adult.
Tom Ward, a public defender representing the boy, declined to comment.
Charles and Marilyn Long, who were in their early 50s, had seven children; four of them are grown and no longer live at home. Marilyn Long homeschooled her kids and ran the children's ministry at the local Evangelical Free Church. Her husband served as an elder there.
Wally Long, the oldest brother of Charles Long, expressed disbelief about the accusations against his nephew, as well as a concern for the boy. The 12-year-old is being held at the nearest juvenile detention facility in Greeley, about 150 miles from his hometown.
"Whatever caused it, he is still who he is. He's still my nephew. And the first question I would ask him is, 'How are you?'" Wally Long said Thursday in an interview broadcast on Denver television stations.
Doctors expect the injured children to fully recover, he said.
Wally Long added his brother and sister-in-law lived for their children and there was nothing to indicate something like this could happen.
"It's a mystery to me. I'm sure it's a mystery to everyone," he said.
The pastor at the family's church agreed, adding he was unaware of any changes in jobs, housing or schooling that the family may have been dealing with.
The Rev. Ron Lee said the 12-year-old boy was involved with church activities, including greeting visitors before Sunday service, running PowerPoint presentations and helping other children memorize Bible verses.
When a school activity prevented the boy from volunteering on Sunday, he called the church to make sure there was a substitute greeter, Lee said.
"He was pleasant, helpful, a good spirit, a good kid," he said. "I'm so shocked. I almost feel like I need to hear from him or one of the children. He's not your typical 12-year-old."
Watson, the district attorney, said he'll take the community's views into consideration as he weighs whether to ask a judge to move the case to regular court and prosecute the boy as an adult. Watson said he'll also consider the boy's circumstances _ such as whether he has any mental health problems _ as he makes that decision.
"I have to be fair to both the community and this young man," Watson said.
His sprawling judicial district on Colorado's sparsely populated Eastern Plains normally goes two or three years without a single slaying. However, Watson said six people have faced murder charges in the district since August.