A man, background, and four young women mourn the victims of a school shooting in the Cathedral of Erfurt, eastern Germany, Saturday, April 27, 2002, the day after a former student of the Gutenberg school in Erfurt killed 16 people before he killed himself. (AP Photo/ MICHAEL PROBST)
Edward C. Allaway, center, alleged killer of seven persons at California State University two days earlier, is led into Orange County courthouse July 14,1976. Allaway, was arraigned on seven counts of murder and held without bail. The prosecution asked for a death penalty under a California provision covering mass murders. Officer escorts are not identified. (AP Photo) (AP Photo/ TMS)
A woman is removed on a stretcher as a friend covers her face while crying at the scene of a shooting rampage at a McDonald's restaurant Wednesday, July 19, 1984 in San Ysidro, California. A gunman opened fire with an automatic weapon killing 20 and wounding another dozen. (AP Photo/Greg Vojtko) (AP Photo/ GREG VOJTKO)
Members of the Edmond, Okla., police department and medical personnel remove one of those killed in a shooting spree Aug. 20, 1986 at the Edmond Post Office in Edmond, Okla. On Aug. 20, 1986, Patrick Henry Sherrill, an ex-Marine and small arms instructor for the Oklahoma Air National Guard, tucked two .45-caliber pistols into his postal satchel, locked the doors and systematically killed 14 people before killing himself inside a suburban Oklahoma City post office. (AP Photo/Steve Gooch) (AP Photo/Steve Gooch)
Ambulance attendants and other workers place one of the sniper's victims in a waiting ambulance during the shooting spree at the University of Texas in Austin, Texas on August 1, 1966. Police said Charles J. Whitman, 25, of Lake Worth, Fla., started the shooting from a sniper's perch near the top of the tower after he killed his wife and mother. Twelve persons were killed at the scene before police bullets felled Whitman. (AP Photo) (AP Photo/ Anonymous)
Blankets cover the windows of a taxi in Hungerford, 60 miles west of London, Aug. 19, 1987, containing the body of one of the victims of gunman Michael Ryan, who opened fire in the town, killing 14 people. Ryan killed himself with a pistol after being surrounded by police. (AP Photo/Dave Caulkin) (AP Photo/Dave Caulkin)
An injured is wheeled away from the University of Montreal on Wednesday, Dec. 6, 1989 after a gunman opened fire in a packed classroom. (AP Photo) (AP Photo/ Anonymous)
Police officers gather outside Luby's Cafeteria in Killeen, Texas, at the scene where a gunman killed 23 people including himself, with semi-automatic gunfire during lunchtime on Wednesday, Oct. 16, 1991. It was the deadliest mass shooting in U.S. history. (AP Photo/Rick McFarland) (AP Photo/ Rick McFarland)
Virginia Tech freshman, Ryan Fowler, second from right, hugs his dad, Tim, of Mt. Airy, Md., as his mother, MaryEllen hugs another student near Norris Hall, the site of a shooting on the campus of Virginia Tech in Blacksburg, Va., Monday, April 16, 2007. Tim and MaryEllen drove down from Maryland to pick up their son after they heard of the shootings. A gunman massacred 32 people at Virginia Tech in the deadliest shooting rampage in modern U.S. history Monday, cutting down his victims in two attacks two hours and a half-mile apart before the university could figure out what was going on and get the warning out to students. (AP Photo/Steve Helber) (AP Photo/ Steve Helber)
Pupils are evacuated from the Jokela high school in Tuusula, Finland, Wednesday, Nov. 7, 2007 where a teenager opened fire at a school in southern Finland on Wednesday, shooting four people - one of them fatally - before being surrounded by police, media reports and a municipal official said. Police confirmed the shooting at Jokela high school in Tuusula, some 50 kilometers (30 miles) north of the capital, Helsinki, but said they could not give details. (AP Photo/Mikko Stig/Lehtikuva) (AP Photo/Mikko Stig/Lehtikuva)
Red Cross workers take away a shocked student at the Kauhajoki School of Hospitality, in Kauhajoki, western Finland, on Tuesday Sept. 23, 2008. A masked gunman whose violent YouTube postings prompted police to question him just a day earlier opened fire Tuesday at his trade school in western Finland, killing 10 people and burning some of their bodies before shooting himself in the head. (AP Photo / Gunnar Bäckman, LEHTIKUVA) (AP Photo / Gunnar Bäckman, LEHTIKUVA)
A sign in front of Flower and Gift World remembers those that lost their lives during last week's shooting rampage by gunman suspect Michael McLendon while funeral services for his mother Lisa McLendon are being held at Samson Baptist Church, seen in the background. (AP Photo/The Dothan Eagle, Jay Hare) (AP Photo/The Dothan Eagle, Jay Hare)
People lay flowers at the site of Thursday's stunning shooting in Baku's Oil Academy, Friday, May 1, 2009. A young man armed with an automatic pistol and clips of ammunition rampaged through a prestigious institute in the Azerbaijani capital Thursday, killing 12 people and wounding others before killing himself as police closed in, the government said. Little is known about the gunman and even less about the motive for the bloodshed that shook the faculty and students of the Azerbaijan State Oil Academy, a noted school whose graduates have included future presidents and tycoons.(AP Photo/Aydin Mamedov) (AP Photo/Aydin Mamedov)
In this image released by the U.S. Army, wounded are prepared for transport in waiting ambulances outside Fort Hood's Soldier Readiness Processing Center Thursday, Nov. 5, 2009, in Fort Hood, Texas. Army psychiatrist Maj. Nidal Malik Hasan is accused of firing more than 100 rounds Thursday, killing 13 and wounding others, in the soldier processing center at Fort Hood. (AP Photo/U.S. Army, Jeramie Sivley) (AP Photo/U.S. Army, Jeramie Sivley)
A crowd gathers outside the elementary school in Dunblane, Scotland, where an unidentified gunman opened fire killing thirteen children and a teacher Wednesday, Mar. 13, 1996. The gunman shot and killed himself following the shootings. (AP Photo/Louis Flood) (AP Photo/Louis Flood)
Emergency personnel treat shooting victims outside the Broad Arrow Cafe near the historical Port Arthur site on Tasmania Sunday April 28, 1996. A gunman with a high-powered rifle opened fire at the popular tourist site Sunday, killing at least 33 people in what police have called Australia s worst massacre in modern history. (AP Photo) (AP Photo/ Anonymous)
From left, Rachel Ruth, Rhianna Cheek and Mandi Annibel, all 16-year-old sophomores at Heritage High School in Littleton, Colo., console each other during a vigil service in Denver's Civic Center Park late Wednesday, April 21, 1999, to honor the victims of the shooting spree in Columbine High School in the southwest Denver suburb of Littleton on Tuesday, April 20, 1999. (AP Photo/Laura Rauch) (AP Photo/Laura Rauch)
James Edward Pough, 42, of Jacksonville, Fla., shown in this Florida drivers license photo, is the suspected gunman that allegedly killed nine people and wounded five others during a shooting spree at the GMAC in Jacksonville, Fla.. (AP Photo) (AP Photo/ Anonymous)
People gather during a candle light vigil to pay tribute to victims of the twin attacks near the Domkirke church on Friday, in central Oslo, Norway, Saturday, July 23, 2011. A massive bombing Friday in the heart of Oslo was followed by a horrific shooting spree on an island hosting a youth retreat for the prime minister's center-left party. The same man, a Norwegian with reported Christian fundamentalist, anti-Muslim views, was suspected in both attacks. (AP Photo/Emilio Morenatti) (AP Photo/Emilio Morenatti)
In this Sunday, March 11, 2012 photo, Afghan soldiers and civilians gather around a truck carrying bodies of civilians allegedly killed in a shooting rampage by a U.S. soldier in Panjwai, Kandahar province south of Kabul, Afghanistan. The United States has paid $50,000 in compensation for each Afghan killed and $11,000 for each person wounded in the shooting spree allegedly committed by a U.S. soldier in southern Afghanistan, an Afghan official and a community elder said Sunday. The sums, much larger than typical payments made by the U.S. to families of civilians killed in military operations in Afghanistan, come as the U.S. tries to mend relations following the killing rampage that has threatened to undermine the international effort here. (AP Photo/Allauddin Khan) (AP Photo/Allauddin Khan)
Parents leave a staging area after being reunited with their children following a shooting at the Sandy Hook Elementary School in Newtown, Conn., about 60 miles (96 kilometers) northeast of New York City, Friday, Dec. 14, 2012. An official with knowledge of Friday's shooting said 27 people were dead, including 18 children. It was the worst school shooting in the country's history. (AP Photo/Jessica Hill) (AP Photo/Jessica Hill)
In this Monday, July 23, 2012 file photo, James Holmes, accused of killing 12 people in Friday's shooting rampage in an Aurora, Colo. movie theater, appears in Arapahoe County District Court with defense attorney Tamara Brady in Centennial, Colo. Colorado prosecutors are filing formal charges Monday July 30, 2012, against Holmes, the former neuroscience student accused of killing 12 people and wounding 58 others at an Aurora movie theater. (AP Photo/Denver Post, RJ Sangosti, Pool, File) (AP Photo/Denver Post, RJ Sangosti, Pool, File)