Rhonda Fields told The Associated Press Saturday.
Police are providing more information on the fatal shooting of four people and the wounding of a fifth person that rocked the quiet community of Grantsville on Friday night. "As for motive, we don't have any of that". Officials said the boy was the only suspect.
Police didn't release any additional details about the shooting, but said the situation was under control and the public wasn't in danger.
"This is very uncommon behavior for our small city, for our neighborhoods", Fields said. His relationship to the victims was not immediately clear.
Fields told ABC News the investigation is ongoing and that because a majority of the victims are juveniles, their names won't be released at this time.
Officers responded to a residence and found four people dead inside - two juvenile girls, a juvenile male and an adult woman, she later told reporters.
She also expressed gratitude for the good working relationship Grantsville has with neighboring agencies, and said police acted quickly and appropriately in their response to what was called in as a possible homicide.
The incident occurred at about 7 p.m. and was called in to 911 by the individual who drove the victim and the suspect to the hospital. Officers arrested the boy there.
The fifth victim had sustained a gunshot wound, was in stable condition and expected to survive, Fields said.
Fields said she didn't know if any of the those killed or injured were related to each other.
"It's an unfortunate tragedy that has taken place here this evening", Marshall said.