Steven Avery's blood was found inside Teresa Halbach's sport utility vehicle, said Calumet County District Attorney Ken Kratz, who plans to charge Avery with first-degree intentional homicide by Tuesday.
"It is no longer a question, at least in my mind as special prosecutor in the case, who is responsible for ... the death of Teresa Halbach," Kratz said.
Avery has denied involvement in the disappearance of Halbach, 25, who was last seen Oct. 31. The freelance photographer had three appointments that day to take pictures of vehicles for sale, including one at a salvage yard owned by Avery's family in Manitowoc County, about 25 miles south of Green Bay.
Days of searching for the Hilbert woman ended Thursday, when authorities announced they had found the burned remains of a woman. Like the SUV, which was spotted last weekend, the remains were found at the salvage yard.
The remains had not been identified Friday, but Calumet County Sheriff Jerry Pagel said investigators believe they are Halbach's.
Blood was found in Avery's trailer home and garage, according to search warrants filed Friday. Eleven spent .22-caliber shell casings also were found in Avery's garage and two guns were found in his home, authorities have said.
Avery, 43, remained jailed after being arrested and charged Wednesday with a weapons violation.
Avery served 18 years in prison for sexual assault but was freed in 2003 after a law school group persuaded a judge to allow new DNA testing, which ruled him out and linked another man to the crime.
Authorities in neighboring Calumet County are handling the case because Avery has sued Manitowoc County over his wrongful conviction.