Varner, 54, made a full confession, prosecutors said, to killing Henderson and his mother, Dorothy Varner, 82. He faces first-degree murder charges in the deaths of his wife and mother, and was ordered held without bond at Lake County Courthouse on Tuesday.
"The nature of this case indicates that he does pose a very significant threat to the people of Lake County, " Lake County State's Attorney Mike Nerheim said.
The offender killed Henderson on October 26, prosecutors said.
"His wife went into the bedroom to go to sleep. The defendant heard her wheezing. He then proceeded to take a machete and strike her about the face with the machete, almost decapitating her," Nerheim said.
For two days, Varner told his mother and brother that Henderson had a headache, prosecutors said. When Dorothy Varner became suspicious, Billy Varner allegedly used a plastic bag and towel to suffocate his mother as she played solitaire in the kitchen.
Varner's brother found their mother's body and called police, who discovered both bodies on October 28. An alert was issued for Billy Varner, who allegedly stole his brother's van and fled. He allegedly robbed a Catholic church with a shotgun November 3 in Williston, North Dakota. No one was injured at the church and he was captured soon after.
The judge said he considers Varner a threat and flight risk.
"Just kind of had me worried for a little while. He was on the loose, and I'm really, I'm glad they caught him," Eric Kosowsky said.
"It's really good that he is gone, that he's off the streets and not gonna hurt anybody else," Amanda Erickson said.