Richard Ryan Laubach is charged with first-degree murder after Elmore County prosecutors say he is responsible for fatal injuries suffered by his 22-month-old stepson — including a broken leg and a fractured skull.

The Ada County Coroner’s office said Joseph Wayne Graham died at Saint Luke's Boise Medical Center Wednesday morning from what appear to be “trauma-related” injuries. Ada County prosecutors said the boy also had significant bruising and brain swelling in addition to the broken bones.

Coroner's officials say the cause of death is abusive head injury and the manner of death is homicide.

Laubach was originally charged with felony injury to child, but Elmore County prosecutors changed that to first-degree murder before he made his first court appearance Thursday. Laubach is now being held in the Elmore County Jail on no bond.

Laubach's next court appearance is set for Friday.

Mountain Home police arrested Laubach in September on misdemeanor charges of domestic battery and injury to child. The child in that case was Joseph Wayne Graham, the same boy who died Wednesday.

Those charges were dropped by Mountain Home City Prosecutor Phillip Miller in December after Laubach agreed to complete an anger-management program, a parenting program, a family safety seminar and two sessions of marital counseling, according to court records.

Court officials said Thursday they never got official confirmation that Laubach completed those requirements.

Mountain Home police have released little information on murder case. All they will say is they were called to an undisclosed Mountain Home residence by paramedics just before 3:30 p.m. Tuesday who had concerns about the injuries suffered by the boy, who was unresponsive.

Paramedics took the boy to Boise for treatment. Mountain Home police say they were able to gather enough evidence to serve Laubach with an arrest warrant at the hospital Tuesday night. Ada County Sheriff’s deputies arrested Laubach and booked him into the jail shortly after 9 p.m. Thursday.

Deputies took Laubach to the Elmore County Jail Thursday.

Prosecutors charged with Laubach with murder in the first degree because they say he killed Joseph Graham while committing an aggravated battery.

The death of the boy is the first homicide case of 2013 in Elmore County.