BERLIN—Bettina Schardt knew that the combination of drugs she drank in the living room of her home in Wuerzburg last week would kill her, and she died alone.

But this was no ordinary suicide. A German doctor told her just the right formula of antimalarial drugs and tranquilizers she needed to commit suicide painlessly—and he set up a camera to film her death.

The case has set off a firestorm here not only because of the way Dr. Roger Kusch has publicized his role in the death—holding a press conference in which he played snippets of the woman’s last moments—but also because of the motives behind her suicide.

The 79-year-old Schardt was not in chronic pain or suffering from a terminal illness. She was healthy and simply wanted to avoid moving into a nursing home.

Today, five of Germany’s 16 states plan to push the federal government to tighten laws on assisted suicide. They want to make it illegal for companies to profit from teaching people how to kill themselves.

German Chancellor Angela Merkel, who leads the conservative Christian Democratic Union, told a German television broadcaster on Wednesday that she opposes assisted suicide “in whatever form it comes.”

But liberal politicians have cautioned against amending suicide laws too quickly.

“No snap decisions,” Peter Struck, parliamentary leader for the Social Democrats, said this week. “No immediate laws that then come to nothing.”

Suicide is not illegal in Germany, nor is assisting one. But mercy killing and euthanasia carry a heavy stigma here because of Nazi eugenics programs that killed more than 70,000 mentally ill and handicapped people before and during World War II.

Kusch, a Hamburg physician and former state justice senator, told Schardt how to take enough of the antimalarial drug chloroquine and the tranquilizer diazepam to make her drift into unconsciousness and then arrest her breathing. He did not administer the deadly mixture and broke no law.

He told reporters in Hamburg on Monday that he set up a camera in Schardt’s home and then let her be.

“I said, ‘farewell,’ and then I left,” Kusch said. He also showed clips of the tape in which Schardt confirmed that she was ending her life of her own free will.

Kusch did not immediately return a phone call seeking comment on Thursday.

In a farewell note addressed to Kusch, Schardt assured him that she planned her own death “smilingly and systematically.”

“Should the manner of my death help you in your fight, my life goal—the freedom to die in dignity—will be achieved,” Schardt wrote.