Officers also encountered Jarron Deajon Pridgeon with a gun and took him into custody.
Hamlin said the suspect and victims all lived in the home, but that the exact nature of their relationships had not been determined.
“It was not random obviously because they all did live in this home together, but as far as what all those relationships look like, we just don't know that yet," Hamlin said.
She said Pridgeon was not cooperating with investigators.
Jail records do not list an attorney who could speak on Pridgeon's behalf.
Muskogee is a city of just under 40,000 people about 45 miles (70 kilometers) southeast of Tulsa.
Man arrested in killing of 5 children, 1 adult in Oklahoma
MUSKOGEE VICTIMS: Brittany Anderson’s family has shared these photos of their loved ones. Brittany (27yo) is still fighting for her life after she, another man, and 5 of her children were shot. The 5 children died.
In the first picture: It’s a few years old. Nevaeh (now 6), Brittany is holding Harmony (now 5), and Que’dynce (now 9). Right top picture: Jaidus (3) Right bottom: Jalayia (2).
The family says Brittany’s boyfriend opened fire on them early Tuesday. Again, shooting and killing the 5 children, shooting and wounding Brittany, and also shooting and killing another man in the home. The suspect is the father of some of the children.
The family said 3 other children in the house were unharmed.
FOX23 Sara Whaley