Heather Mack, stands at the police district headquarters after she was brought in for questioning in relation to the death of her mother, in Bali, Indonesia. Pic: AP.

BALI, Indonesia (AP) — Police investigating an American couple suspected of killing the woman’s mother at a resort hotel on Indonesia’s Bali island say the three had a disagreement over who was paying for the rooms but that a motive for the crime has not been established.

Heather Mack and her boyfriend, Tommy Schaefer, have been declared suspects in the killing of Mack’s 62-year-old mother, Sheila von Wiese-Mack, whose body was stuffed into a suitcase.

Naming someone a suspect is a formal step under Indonesian criminal law meaning police are preparing to bring charges.

Bali police chief Maj. Gen. Benny Mokalu said Wednesday officers had interviewed 19 witnesses, some of whom cited a disagreement between the three over who should pay for the rooms.

Mokalu said a motive has not been established.

On Wednesday a lawyer said the couple were being held under a suicide watch.
Indonesian lawyer Haposan Sihombing said Mack and Schaefer are still refusing to talk to investigators. The body of 62-year-old Sheila von Wiese-Mack was found last week inside a suitcase in the trunk of a taxi in front of an upscale Bali hotel. The couple was arrested the following day.

Haposan said Wednesday that Mack is being detained at the Denpasar police station and Schaefer is being held separately at the provincial police headquarters.

An autopsy found Wiese-Mack died of asphyxiation after her nose was broken by a blunt blow.