New information from two sisters who were 11 and 13 when their mother was killed in 1982 in northern Wisconsin resulted in a murder charge against their father more than 35 years later, a lead investigator in the case said Wednesday.

Robin Mendez, 69, was charged with first-degree murder this week in the death of his wife, Barbara Mendez.

Oneida County Sheriff's Capt. Terri Hook said recent interviews with the couple's daughters — as well as a woman who said she had a sexual relationship with the defendant when she was 14 — helped lead to the murder charge.

"There are witnesses that are ready to talk and ready to provide information that they wouldn't have been able to provide (in the past) based on their relationship with him," Hook said.

According to the criminal complaint, the couple's daughters, Dawn Mendez Shape and Christy Mendez Wadas, recently told investigators they were manipulated and coached by their father on what to say when the case was initially investigated.

The daughters also told investigators they were aware that their father was spending a lot of time with the 14-year-old girl in 1982, according to the 36-page complaint.

Barbara Mendez was found bludgeoned to death at her workplace, the Park City Credit Union in Minocqua, in April 1982. She died from multiple blows to her head, mostly likely with a pry bar, according to the complaint. Robin Mendez used that type of pry bar frequently at his family's furniture business, prosecutors said.

The woman who said she had a sexual relationship with Mendez when she was 14, also recently told investigators she believed Mendez wanted her to provide an alibi for him the day his wife was killed, so she initially lied to police and told them she was on the phone with him during the time his wife was killed, the according to the complaint.

Hook said renewed investigative work on the cold case in 2002 and 2003 focused on Robin Mendez's DNA found at the crime scene. The charges filed in the case this week are based largely on circumstantial evidence, not DNA, Hook said.

"Right from the very beginning Mendez was giving statements on why physical evidence from him would be at the bank," she said.

Hook said the addition of two detectives to the small sheriff's department last fall allowed them to devote time to the case and re-interview all surviving witnesses.

"Some people were still around and had excellent memories because of how traumatic the case was," Hook said.

Mendez is being held in the Oneida County Jail on $250,000 bond. Minocqua, a town of 4,400, is about 285 miles (458 kilometers) northwest of Milwaukee.