The counselor was killed Saturday at Wayfinder Family Services in the Windsor Hills neighborhood of Los Angeles.
Homicide detectives say the counselor, David McKnight-Hillman, was trying to break up a fight between the teens when he was attacked.
Two of the teens are 18 years old and have been booked on charges of murder.
They are identified as Nyier Mason and Keith Lewis.
Five teens under the age of 18 are not being identified, but are expected to also face murder charges.
One of the five juveniles escaped from the scene Saturday night and is wanted by detectives.