Skyler T. Schneider, 21, of Helena is being held in connection with the fatal Saturday night shooting of a 23-year-old woman.
A news release from the Helena Police Department said Schneider was to face charges of deliberate homicide and tampering with evidence.
The name of the victim has not yet been released by authorities.
The Law Enforcement Center dispatch received a 911 call at 11:39 p.m. Saturday of a woman having been shot.
Schneider called to report the shooting and provide the location, in front of 29 12th Ave., where the victim was in a vehicle, according to Helena Police Department Assistant Chief Steve Hagen.
Schneider and the victim were boyfriend and girlfriend, and the victim sustained a single gunshot wound to the head, Hagen wrote in an email.
Officers who responded found the woman who was then transported to St. Peter's Hospital where she died, according to the police department statement.
Life-saving measures at the hospital were deemed unsuccessful at 1:43 a.m., Lewis and Clark County Coroner Bryan Backeberg said.
Schneider is being held in the Lewis and Clark County detention center.
Police recovered a 9mm handgun believed to have been used in the shooting, Hagen said.
This story will be updated as more information is released by the police department.