A 32-year-old Butte man is charged with killing his 8-week-old daughter last month.
Matthew John Blaz was arrested Thursday and is charged with deliberate homicide in the Aug. 16 death of Mattisyn Jolene Blaz.
Charging documents say the baby's death was originally reported as an accidental fall, but an autopsy determined Mattisyn died of abusive head trauma. Court records say Blaz was with the baby at the time she suffered the fatal injuries.
Butte police tell NBC Montana the charges are the result of a more than month long investigation.
32 year old Matthew John Blaz faces one count of deliberate homicide.
According to investigators, Matthew Blaz initially claimed the girl was injured in a accidental fall, but the state medical examiner disputes that claim, saying the girl died from abusive head trauma.
Butte-Silver Bow Sheriff Ed Lester said when the call came in to 911 on August 16, Blaz told dispatchers his daughter wasn't breathing.
Emergency workers rushed the girl to St. James Hospital, where she was later pronounced dead.
Investigators sent Mattisyn's body to the state crime lab in Missoula to determine the cause of death.
Lester explained that anytime a child this age is the center of an investigation like this, it is difficult for everyone involved.
"Anytime there's a child injured or killed, it's difficult on the family members," he explained, "but it's difficult on the responders as well, and the investigators as they proceed through a case like this. It's hard on everyone involved in a case like this, including the medical people who have to deal with that kind of trauma also."
Blaz is being held in the Butte-Silver Bow Detention Center on a $500,000 bond.
Montana code states a conviction on deliberate homicide carries a minimum sentence in of 10 years in prison.
Blaz will be arraigned in District Court in the next few weeks.
We'll have more details on the case as it develops.