Kyle Flack, 27, of Ottawa, Kan., was in custody, the Kansas City Star reported. He was expected to be formally charged Friday with at least three counts of murder.
Police found the bodies of Kaylie Bailey, 21, Andrew Stout, 30, and Steven White, 31, earlier this week. Stout lived at the farm near Ottawa, White was one of his roommates and Bailey went there last week to visit with her daughter, Lana-Leigh Bailey, 18 months.
Flack had also been living there but Stout had ordered him to leave, investigators said.
Franklin County Sheriff Jeffrey Richards said investigators searched for Lana-Leigh's body Thursday after getting information that suggested she had been killed. He said deputies on horseback, using all-terrain vehicles and on foot were involved.
"It is a large area and we have to be very meticulous in what we are doing," he said.
Shawn Bailey, the little girl's father, is in prison, and Kaylie had filed for divorce. Rachel Helms-Bailey, Shawn's mother, said she had received little information.
"I was hoping she was alive," Helms-Bailey, said of her granddaughter. "I want to know how she died; they will not tell me."