Manuel Balce Ceneta/AP Photo

WASHINGTON - Nearly six months after the massacre at Sandy Hook Elementary School, the parents of the Newtown, Conn., children killed there are back on Capitol Hill this week, lobbying for tougher gun legislation to prevent tragedies like the one that left 20 students and six educators dead in December.

Several Newtown families met with members of Congress on Tuesday to pressure lawmakers to continue work on the expansion of background checks.

The families plan to meet with Sen. Joe Manchin, D-W.Va., one of the architects of the failed background check bill, and in the afternoon, the Newtown parents are scheduled to attend a meeting with House Speaker John Boehner and House Majority Leader Eric Cantor.

The Newtown families were last on Capitol Hill when the gun bill failed to pass the Senate less than a month ago, a moment President Obama called a "shameful day for Washington." Shortly after the Senate voted against the plan, several parents whose children were killed at Sandy Hook appeared alongside the president at the White House as he vowed to continue the fight to enact stricter gun laws.

"I see this as just round one," Obama said in April. "I believe we're going to be able to get this one. Sooner or later we are going to get this right. The memories of these children demand it, and so do the American people."

But as they make their way back to Capitol Hill this week, the Newtown families are trying to reignite their issue at the same time as Washington is focused on a series of scandals, including top secret leaks from the National Security Agency and the targeting of conservative groups by the IRS, along with the Senate beginning debate on immigration reform.

Since the Senate bill failed last month, the White House has exerted little public pressure on the issue of gun reform, but that may soon change. Earlier this month, Obama and Vice President Joe Biden hosted a mental health conference at the White House, and an aide to the vice president confirmed to ABC News that Biden is planning an upcoming event on gun control.

While Washington has directed little focus to the issue of gun control in recent weeks, the Newtown families have continued their campaign for solutions to gun violence. They have taken their fight to the local level, advocating for the strengthening of gun laws in states like Delaware and New Jersey, and as the Washington Post detailed this weekend, the families are still dealing with the emotional toll of losing their young children.

In addition to their meetings with lawmakers this week, the Newtown families plan to commemorate the six-month anniversary of the Sandy Hook tragedy with additional events.

On Thursday, friends and families from Newtown, including Jillian Soto, whose sister Victoria Soto was one of the teachers killed last December, plan to form a human "Ribbon of Remembrance" in front of the Capitol and hold a news conference with lawmakers.

In Newtown on Friday, Mayors Against Illegal Guns say they will launch a bus tour called "No More Names: The National Drive to Reduce Gun Violence" to convince senators to reconsider the background check bill.