Emanuel Doll, 25, is accused of killing his twin sister’s son with an ax at their father’s Broomfield home on April 27.
According to court documents, Doll's parents picked up their 4-year-old grandson that morning so their daughter could go to nursing school. Back at their house, the boy was on the couch playing on his iPad when his uncle asked the boy to come down to the basement with him.
Not long after that, the grandmother said she heard loud noises and yelled to her son asking what it was.
Doll told her it was nothing. Then a few minutes later, he came upstairs and went out the back door.
The grandmother went to the basement and found the 4-year-old dead on the floor with blood everywhere and an ax nearby, according to court documents.
After the homicide, neighbors said police were often called to the home.
"It always bothered me and bothered my wife a lot about whats really going on over there. So it's not like it's unfamiliar with the cops, they all know," neighbor Jim Egli told KDVR.
"Just a shock and it really takes a toll on you, on your heart, it's depressing to hear something like that," said another neighbor, David Platz.
Doll was arrested in the backyard of his parents' home the day of the killing. Neighbors say he still lived at home and worked for his father's company.
He is being held at the Broomfield jail without bail on a first-degree murder charge.
His next court date is July 14.