Jakarta, Indonesia (CNN) -- The cabbie probably thought nothing of it when the young couple left their large hard-sided suitcase in the trunk of his car and went back into the five-star hotel.
They said they needed to find the other person they were with and to pay their bill.
But after a lengthy wait, the young man and woman still hadn't returned. Puzzled, the driver called hotel security.
The suitcase in the trunk looked very odd. It was wrapped in a bedsheet. Then the cabbie saw blood.
When authorities at the South Kuta station in Bali, Indonesia, opened the case, they found inside the badly beaten body of Sheila von Weise Mack, wrapped in a blood-stained bedsheet.
Two smaller suitcases were found in the St. Regis Bali Resort garden. Both contained hotel towels with blood on them, according to police.
Those are the events that police say unfolded Tuesday. Mack, 62, of Chicago, had been staying at the posh St. Regis with her daughter, Heather Mack, and the daughter's boyfriend, Tommy Schaefer.
The daughter and her boyfriend were found Wednesday morning at another hotel about 15 kilometers (9 miles) away. The couple's St. Regis room was "very messy," with clothes still inside.
The couple told police they had been taken captive at the resort by an armed gang, whose members killed Sheila von Weise Mack, but they escaped, CNN affiliate Trans TV reported.
Djoko Hari Utomo, police chief of Denpasar, the capital of Bali, said Thursday that the pair have been declared suspects in the case. According to Indonesian law, police can keep suspects in custody for up to 20 days.
Djoko said that police hadn't found anything on surveillance camera footage from the hotel that supported the claim of an attack by an armed gang. He said the footage showed the mother and daughter arguing near the hotel's front desk on Tuesday.
A lawyer appointed for the couple told Reuters that Heather Mack didn't want to comment on the incident. She repeatedly asked for a lawyer from the United States, he said.
Djoko said Thursday he was looking into whether it was possible under Indonesian law to meet that request.
The two suspects will be questioned separately, he said. Police also plan to carry out psychological assessments of the couple.
U.S. officials will offer consular guidance to the two Americans.
A doctor who examined the body said that judging by the bruises and other wounds, Mack was struck on the face and other parts of her head with a blunt object. She also had a gash on her forehead.
Dr. Ida Bagus Putu Alit told CNN that there was evidence -- a broken fingernail and bruises on both wrists -- of an apparent struggle.
A spokesman for the St. Regis, where rooms go for $500 to $8,200 a night, said the hotel staff is "deeply saddened" by the incident and is doing all it can to assist investigators.
A profile of Mack published by The Caxton Club of Chicago (PDF) says she worked for Edward M. "Ted" Kennedy, the late U.S. senator from Massachusetts, and studied with Pulitzer Prize-winning writer Saul Bellow for 10 years.
For years, the Macks lived in the affluent suburb of Oak Park, Illinois.
An Oak Park police spokesman said a quick check showed officers had gone to the family's home 86 times between 2004 and 2013. The calls were for a variety of reasons including domestic trouble, missing persons reports and followups to 911 hangups, David Powers said. There were no records that anyone was arrested, he added.
A man who said he was the Macks' neighbor told the CNN affiliate WGN that Sheila von Weise Mack moved last year in hopes it would help improve family relations and for her to be closer to the arts.
"She was very much involved in the arts so you would see her at concerts, you'd see her at lectures," Allen Parchem told the station. "I knew that she had a very active arts life downtown too, attending events, so with the move to downtown I think she was hoping to be even more a part of that scene."
A friend of the family described her as warm and thoughtful. Mark Bacharach, who had known her for 27 years, said she "did not have a condescending, malicious bone in her body."
Bacharach said mother and daughter had a tumultuous relationship.
"(Heather) could be extremely charming to guests, but mean to her mother," he said.
Sheila von Weise Mack's husband, James, was a well-known figure in the Chicago music scene, having worked on dozens of albums. The Chicago Tribune reported he died of a pulmonary embolism in Athens, Greece, during a family vacation in 2006.
CNN's Roger Clark reported from Jakarta and Steve Almasy reported and wrote from Atlanta. CNN's Brian Todd, Pamela Brown, Eric Marrapodi, Joshua Berlinger, Brian Walker, Shawn Nottingham, Jethro Mullen and journalist Tasha Tampubolon contributed to this report.