Flags fly at half-staff Tuesday after the deadly shootings at the Navy Yard in Washington, D.C. J. Scott Applewhite/AP hide caption

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Kathy Gaarde, one of the people killed in Monday's shootings at Washington's Navy Yard, in a family photo. Her husband, Douglass, says the picture depicts Gaarde "with her 94-year-old mother who she cared for until she passed away last year." Douglass Gaarde hide caption

itoggle caption Douglass Gaarde

President Obama walks out to deliver remarks on the economy at the White House on Monday. At the beginning of his news conference, Obama commented on the shootings at the Navy Yard. Pablo Martinez Monsivais/AP hide caption

itoggle caption Pablo Martinez Monsivais/AP

A tribute page to Christopher Lane, an Australian college baseball player who was shot and killed in Oklahoma last week, has drawn thousands of responses on Facebook. Facebook hide caption

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Homicide remains a leading cause of death for young people, even as rates drop. In Chicago, a teenage boy grieves next to a memorial where Ashley Hardmon, 19, was shot and killed on July 2. Gunmen fired while she was chatting with friends. Scott Olson/Getty Images hide caption

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Older men may have guns in the home that can pose a risk when people are depressed or not thinking clearly. iStockphoto.com hide caption

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A young neighbor watches as police respond to a double homicide in Flint, Mich., on June 30. Organizations including the Michigan Youth Violence Prevention Center are working to help young people choose non-violent solutions to conflict. Michelle Tessier/MLIVE.COM /Landov hide caption

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Student Kahlil Quato fights tears as he speaks at a University of Chicago candlelight vigil in 2007. The service was held in remembrance of Amadou Cisse, a graduate student, who was shot to death at point-blank range. Stacie Freudenberg/AP hide caption

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The U.S. rate of gun homicides and other crimes fell after 1993, according to two studies released Tuesday. But a survey showed that only 12 percent of Americans said they felt gun homicides had fallen. Scott Olson/Getty Images hide caption

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Chris Colwell, director of emergency medicine at Denver Health, has treated victims from two of the deadliest mass shootings in the U.S. He says he's deeply disturbed by how easy it is to get guns. Barry Gutierrez/for NPR hide caption

itoggle caption Barry Gutierrez/for NPR

At a Chicago funeral home last week, a painting of 15-year-old shooting victim Hadiya Pendleton stood at the entrance. Scott Olson/Getty Images hide caption

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President Obama signs a series of executive orders Wednesday about the administration's gun law proposals as Vice President Biden and children who wrote letters to the White House about gun violence look on. Chip Somodevilla/Getty Images hide caption

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