Lawyers representing an American couple on trial in Indonesia argued Tuesday that there is no evidence of premeditated murder in her mother's death and sought light sentences if they are convicted.

Prosecutors want jail sentences of 18 years for Tommy Schaefer and 15 years for Heather Mack if they are found guilty of murdering Sheila von Wiese-Mack, 62, whose badly beaten body was found in a suitcase in the trunk of a taxi outside an upscale hotel in August.

Schaefer, 21, and Mack, 19, both from Chicago, are being tried separately with the same judges and prosecutors at the Denpasar District Court. They are charged with premeditated murder, which carries a maximum death penalty, and the judges could ignore the sentencing requests.

Ary Soenardi, a lawyer for Mack, said his client has apologized and still regrets what happened.

"The defendant still regrets and feels sad over the death of her late mother," Soenardi said. "As the only child, the defendant has lost the love of a mother."

He doubted how the prosecutors concluded that Mack committed a premeditated murder, since none of 22 witnesses heard in the trial knew exactly what was really done by the defendant.

Therefore, he hoped that the judge would "take into account the social and psychological conditions of the defendant in deciding the verdict and hand down as light as possible sentence."

Prosecutors have accused her of committing sadistic acts to her own mother, but decided to be lenient because she repeatedly expressed remorse and has a newborn baby. However, they did not explain why they sought less than the maximum penalty for Schaefer.

In Schaefer's trial, lawyer Iswahyudi Edy said the 18-year year term is too heavy as the prosecutors could not prove premeditation.

"The crime done by the defendant was actually preceded by a series of incidents including a quarrel between Mack and her mother, who threatened to kill the unborn baby," Edy said. "Mack called the defendant through a short message ... and the defendant just came to protect Mack without intention to kill the victim."

He cited confessions from both Schaefer and Mack in which they said the attitude of von Wiese-Mack could have been to blame, since she could not accept her daughter's pregnancy.

Prosecutors have asked the judges to declare the defendants guilty of premeditated murder with the fact that Schaefer deliberately brought a metal fruit bowl when he came to the room at the St. Regis where Mack and her mother were staying. The bowl was the weapon used to strike her. They said Mack helped stuff her mother's body in the suitcase by sitting on it to enable Schaefer to close it.

Both Soenardi and Edy argued that the defendants deserve light sentences since they are still young and regret their deeds.

Presiding judge Made Suweda adjourned the hearing until Thursday to give prosecutors the chance to defend their charges.