A 12-year-old boy who on Saturday allegedly stabbed his teenage brother in the chest and killed him is in custody and now charged, authorities said.

The boy was initially released to his family but is now being held at the Hennepin County Juvenile Detention Center.

The Hennepin County Attorney's Office charged the boy Monday in juvenile court. 

"Because of his age, no other information is public," a statement from the office read late Monday afternoon. Defendants ages 16 and 17 charged with a felony do have their identities and the charges made public.

Typically, details about any allegations are released when charges are filed in adult or juvenile court. Those are not being disclosed in this case, nor has the County Attorney's Office said what specific criminal count or counts were filed.

Police said the 12-year-old used a kitchen knife to kill his 16-year-old brother. Neither the suspect’s nor the victim’s name has been released by Tuesday morning. 

“The mother and other family members were home at the time of the incident,” said a police statement. “Police are working with the family to determine the circumstances that led to the stabbing.”

The incident occurred about 8 p.m.  at the Crown Ridge Apartments in the 11300 block of Fairfield Road.

“We know there was some sort of an altercation between the two boys,” Minnetonka Police Chief Scott Boerboom said at a news conference Sunday.

Officers attempted to resuscitate the 16-year-old, who was taken to North Memorial Health Hospital in Robbinsdale, where he was pronounced dead.

The  suspect was uninjured but taken to the University of Minnesota Medical Center-Fairview for evaluation.

The victim attended Hopkins High School, where counselors and other professionals were on hand Monday to talk to his classmates and friends about their grief, said Jolene Goldade, spokeswoman for the School District.

In such a situation, the district typically keeps counselors in the building as long as necessary. “It’s a very shocking situation,” Goldade said. “I can’t speak for how the building is doing.”

On Monday at the Crown Ridge Apartments, which are operated by CommonBond Communities, staffers with the affordable housing nonprofit were offering snacks and providing a place for residents to talk.

“We are just so deeply saddened,” said Alicia Cordes-Mayo, CommonBond spokeswoman. “It’s just heartbreaking.”