It will never be known what transpired between an elderly couple in their Skowhegan bedroom before the husband shot his ailing wife and then himself.

There was no note explaining the deaths of 85-year-old Barbour Flewellen and his wife, Marie, 75. Barbour Flewellen’s last known words were spoken to Skowhegan police dispatchers when he called to report two “mercy killings” on the morning of May 24.

What we do know is that the elderly are the most likely to commit suicide in both Maine and the United States, a statistic primarily driven by older, white men.

In fact, males of all ages are far more likely to kill themselves. Of the approximately 190 people who kill themselves each year in Maine, about 80 percent are male.

Karen Mosher, clinical director at Kennebec Behavioral Health in Waterville, said a suicidal crisis generally involves a belief that the emotional or physical pain someone is experiencing is intolerable, inescapable and interminable.

Counseling people with a desire to commit suicide usually involves working on those elements, Mosher said, to help them feel more in control, able to change their circumstances and able to understand that the situation will not last forever.

Socially isolated people are more vulnerable, Mosher said, and family and friends should watch for signs of increased risk. People more likely to commit suicide may think or talk about suicide, abuse alcohol, withdraw, act recklessly, have mood swings, or feel purposeless, anxious, hopeless or angry.

“If you’re worried about them, talk to them. There’s no harm in asking people if they’re all right, even if they’re contemplating suicide. That will not make them more suicidal,” Mosher said.

Murder-suicides are again in the spotlight, because of both the Skowhegan killings and the shooting death last Monday of Sarah Gordon, 30, in Winslow, by her 32-year-old husband, Nathaniel Gordon, who then killed himself.

Murder-suicides are relatively rare compared to suicides and homicides, but they’re “an emerging public health concern,” according to a study published in 2005 in the American Journal of Geriatric Psychiatry. The “rate may be increasing in the United States, especially among older persons,” the study said.

The study compared older married men who commit murder-suicide with those who commit only suicide.

It found that older men who committed murder-suicide were more likely to be caregivers for their wives. Older men who committed suicide, in comparison, more often had health problems and were the ones receiving care.

Depression also played a significant role, the study found, and socioeconomic status was not a factor.

The largest percentage of people who commit suicide in both Maine and the United States — 14 percent of all suicides — are older than 70, according to statistics compiled between 1999 and 2005 by the Suicide Prevention Resource Center, based in Newton, Mass.

The American Foundation for Suicide Prevention compiles data in slightly different age groups and relies on 2007 information.

In that year, it reported that the greatest number of suicides in the United States was among those ages 45 to 54, at 17.7 suicides per 100,000 people. The second-highest rate was among people from 75 to 84 years old, at 16.3 suicides per 100,000 people.

Maine had the 14th-highest rate of suicides in the country in 2007 — at 14.5 suicides for every 100,000 people, according to data from the foundation. The national rate was 11 per 100,000. The District of Columbia had the lowest rate of suicides, and Alaska had the highest.

Details about the lives of Barbour and Marie Flewellen are limited. Their neighbors on Alder Street described them as sweet people who helped others. They said the couple had moved from Charlottesville, Va., about a year ago and that Marie had not been well this winter.

A family member in Maine declined to comment, and others did not return phone calls.

According to an online list of gravestones at Maplewood Cemetery in Charlottesville, the Flewellens’ 14-year-old son died in 1989, and their 27-year-old daughter died in 2004.