"Sometimes it's done strictly out of illness and depression, but if it's an act of love, they have been through life and death and raised their children and gone through being married for better or worse," she said. "With a long-term couple, they say, 'Let us die together.'"
Society needs to be more tolerant of these choices, Lynn said, but at the same time, "We can't put our seniors out on an iceberg like the Eskimos."
There are no statistics available for how many couples die in suicide pacts, but Americans over 65 are more likely to die by suicide than their younger counterparts, according to the National Institute of Mental Health (NIMH).
While the elderly make up only about 12 percent of the population, they account for 16 percent of the suicides.
Seniors have a suicide rate of 14 out 100,000; the general population rate is 11 for every 100,000 deaths. For non-Hispanic white males over age 85, the rate is nearly 50 per 100,000, according to NIMH.
When Mary Witte found her parents in Milwaukee, beside their bodies was a briefcase containing a copy of the book, "To Die Well," and a DVD by author Derek Humphry, founder of the former Hemlock Society, now Compassion and Choices. Her father also left a note for his family.
The method he had chosen, inhaling helium and putting a plastic bag over the head, is recommended in the book.
"My mother started slipping at the end of 2007," Witte said. "My father did not want anyone taking care of them. She saw both of her parents die in a nursing home and my father swore they would not go to a nursing home. They made the choice together."
"I was so scared," said Witte. "Mom was so close to wiping out and breaking a bone and going into a facility, and then they would have had no control over it."
Two years ago, the couple began talking about suicide seriously.
Gute tried to gird up the courage twice in the last month, but failed, said Witte.
He discussed it with his three girls, Witte and two other sisters, 46 and 42.
"He wanted us on board," Witte said. "He had written all three of us a letter to say goodbye. ... We kept thinking they wouldn't do it."
"The irony was he was going to do it in a hotel, because he didn't want to taint the house or have us find him," she said.
But a dear friend and fellow doctor who knew about the plan convinced the Gutes that it would be "traumatic" for someone outside the family to find them and perhaps be blamed.
The day of their deaths, Witte called the house all day and got no reply.
That evening, she and her husband, an environmental lawyer, and their 17-year-old son -- who had also had a "talk" with his grandfather about his choice -- checked at the house.
Another sister, who had an earlier conversation with her parents, suggested looking in the garage.
"We reluctantly drove over nervously and the house was quiet," she said. "It was very strange, awful, and I was inconsolable."
Many Americans are still morally squeamish about suicide, despite stories like those of the Gutes.
Bill Jose, who has a Ph.D. in social psychology, recently led a special interest group discussion on suicide at the Osher Institute of Learning at the University of Southern Maine in Portland for seniors aged 65 to 80.