(Carolyn Kaster/AP Photo)

WASHINGTON - As the nation comes to grips with this week's killing of 12 people at the Washington Navy Yard, the president and first lady plan to meet with the victims' families Sunday ahead of memorial services for those they lost.

The memorial will be held at the Marine Barracks Washington, a historic building not far from where former Navy reservist and contractor Aaron Alexis opened fire inside the office where he had recently been employed. The 34-year-old appears to have fired indiscriminately at anyone who roamed its halls before he was killed by first responders.

In the FBI Director's Own Words: A Chronology of What Happened at the Navy Yard

Six days will have passed for the country to piece together what led to the tragedy and begin the long road to recovery. The Navy has set up round-the-clock counseling stations at the yard and nearby Joint Base Anacostia-Bolling; on Wednesday evening Vice President Joe Biden visited the eight wounded - all are expected to survive.

According to The Associated Press the Navy has extended invitations to roughly 4,000 people for the service, which is closed to the public.

For President Obama, such somber occasions have become all too familiar.

There have been five prior mass shootings since the president assumed office: Binghampton, N.Y., (2009); Fort Hood, Texas, (2009); Tucson, Ariz., (2011); Aurora, Colo., (2012); and most recently the killing of 20 children and six adults in an elementary school in Newtown, Conn., last December.

Obama has spoken at the memorials for four of those shootings. And although he did not attend the formal program in Aurora, he met personally with the families of the dozen killed and 58 wounded on the day of that service.

The White House has offered no guidance on the themes Obama may hit during his remarks at the barracks, but with prior tragedies from shootings to tornado disasters he has been faced with providing comfort while also offering a path forward.

READ MORE: From Newtown to the Navy Yard, Another Moment for Gun Control Advocates?

On the day of the Navy Yard shooting the president expressed his frustration with the high frequency of such tragedies when he called it, "yet another mass shooting," and again hinted at the limits of his power in a televised interview the following day.

Speaking with Spanish-language network Telemundo he suggested that stronger background checks on gun purchases might have prevented this latest attack.

"Initial reports indicate that this is an individual who may have had some mental health problems," he said. "The fact that we do not have a firm enough background-check system is something that makes us more vulnerable to these kinds of mass shootings."

Aaron Alexis is known to have displayed a documented history of mental health problems, including paranoia, but passed a federal background check when he purchased a shotgun and ammunition from a Virginia gun store two days before the rampage.

A May ABC News/Washington Post poll found 83 percent of Americans support expanded and strengthened checks for all sales, but movement on heightened gun control remains stalled in Congress.