A 28-year-old Allentown woman was arrested this weekend for her role in last week's home-invasion robbery in Upper Saucon Township.

Three days after a woman went missing during a daytime home-invasion robbery at a posh Upper Saucon condo that left police seeking a motive, investigators now believe they have one: The woman's jilted girlfriend kidnapped her to get her back.

Police arrived Wednesday at W. Russell Yurchak's home in the 5400 block of Boulevard Grand Cru to find a shower running, a bed undone in a spare bedroom where the woman had lived and women's clothing scattered throughout it.

The woman, who was employed by Yurchak, was gone and police were unsure if she was taken or left willingly with the robbers who made off with Yurchak's Mercedes-Benz and other items.

Police listed the woman as endangered in the national crime database. On Saturday, Allentown police found a woman matching her description.

Katherine Frank was found in the 600 block of Chew Street, along with her estranged girlfriend, whom police charged with kidnapping Frank.

Nakia M. Rivera, 28, admitted during an interview that she was upset when Frank left her and wanted her back, according to court records. She also told Frank she would kill her if she tried to leave, according to court records.

Frank had been staying at Yurchak's home to get away from Rivera, who had punched her in the nose during an argument two weeks earlier, according to court records. Upper Saucon police said Frank was working for Yurchak, helping transcribe notes for a book he is writing on financial advising.

According to a criminal complaint:

Rivera told police she contacted an unidentified man to take her to Yurchak's home, which is part of the Epernay subdivision, a neighborhood of million-dollar homes near Saucon Valley Country Club and just east of Route 378. Most of the condo homes in the community, which is still under construction, are vacant.

Three men, one of them armed with a gun, came with Rivera to Yurchak's home at 10:30 a.m.

Rivera knocked on the door and asked for "Katie," his house guest. Yurchak said Rivera, whom he did not know, went upstairs and then several men barged into his home, one of them pointing a gun and ordering him to sit on a chair in his living room.

The armed man tied Yurchak's hands with an electric cord and the group rummaged through the house, taking Yurchak's credit cards, driver's license, cellphone, cordless home phones, $300 cash and his Mercedes-Benz. Yurchak said he waited for the group to leave before calling for Frank.

After untying the electrical cord the robbers wrapped around his hands, Yurchak yelled for Frank, got no response and called police.

Upper Saucon police and Allentown police interviewed family and friends of Frank and no one had seen or talked to her since the abduction. Upper Saucon police said her phone had been left behind at Yurchak's home.

The missing Mercedes was found in Allentown on Thursday.

Allentown police were dispatched at 6 p.m. Saturday to the 600 block of Chew Street on a report of a woman matching the description of Frank. When police found the two women, Rivera initially gave a fake name.

Allentown police did not say who called them or if Frank appeared to be in distress. People who live in the area said police searched two buildings, kicking in the door of one.

Frank said she left the apartment she shared with Rivera two weeks ago because she was afraid after being assaulted by her. She said she was in the shower at Yurchak's home when Rivera pulled her out, wrapped her in a towel and placed a blindfold over her eyes.

Frank said she was taken by vehicle to several homes in Allentown and was threatened with being killed if she tried to escape.

Rivera said she went to get Frank from Yurchak's home because she feared she would never see her again. She admitted threatening Frank if she tried to leave.

Rivera was charged with kidnapping for ransom, kidnapping to inflict injury or terror, robbery, theft, receiving stolen property, unlawful restraint, false imprisonment, simple assault and criminal conspiracy. She was also charged with false identification to law enforcement.

She was arraigned by District Judge Robert Halal and sent to Lehigh County Jail under $755,000 bail.

Rivera has a lengthy rap sheet that includes assaults, weapons violations, disorderly conduct and lying to police, according to court records.

A woman at the home where Rivera allegedly lived said she did not know anything about the case.

Lehigh County District Attorney Jim Martin said the case is still under investigation. He did not have any description of the others involved.

manuel.gamiz@mcall.com

610-820-6595