This month alone, at least four shootings of students have occurred in schools across the country, including Monday's deadly attack outside Cleveland, Ohio.

Experts say the spate of shootings may be coincidental and not indicative of a troubling trend. They note that, overall, crime and violence in America's schools have been declining in recent years. And murders are particularly uncommon.

A teenager opened fire as students ate breakfast in the cafeteria at his suburban Cleveland high school Monday, killing one student and wounding four others before he was chased from the building by a teacher. The suspect, whose name was not released because he is a juvenile, was arrested near his car a half-mile away, authorities said.

A student who saw the attack up close said it appeared the gunman targeted a group of students sitting together. One teacher was said to have dragged a wounded student into his classroom for protection.

FBI officials would not comment on a motive for the shooting, which sent students screaming through the halls at the start of the school day at 1,100-student Chardon High, in the town of 5,100 people 30 miles from Cleveland. Fifteen-year-old Danny Komertz, who witnessed the shooting, said the gunman was known as an outcast who apparently had been bullied. But other students disputed that.

"Even though he was quiet, he still had friends," said Tyler Lillash, 16. "He was not bullied."

Two of the students, both male, are in critical condition, another is in serious condition and a 17-year-old girl is in stable condition, officials said.

The slain student, Daniel Parmertor, was an aspiring computer repairman who was waiting in the cafeteria for the bus for his daily 15-minute ride to a vocational school.

Homicide in a school setting "is a rare event,"said Jennifer Truman, a Bureau of Justice Statistics statistician and co-author of a new federal report on school violence.

The study counted 17 homicides of school-age youths at U.S. schools from July 1, 2009, through June 30, 2010, which was "the same as the year before," Truman said. The annual report, released last week, is a joint effort by the Bureau of Justice Statistics and National Center for Education Statistics.

Even so, the February shootings, along with confiscations of high-powered weapons in other school hallways this year, are noteworthy.

According to news accounts, the following shootings occurred this month:

On Feb. 10 in Walpole, N.H., a 14-year-old boy shot himself in the face in a crowded elementary-school cafeteria. The teen, who police said was upset by a "relationship issue," survived.

On Feb. 20, two teens wielding guns shot at a group of kids at a Murfreesboro, Tenn., school. A 14-year-old student was shot twice in the leg. The shootings allegedly stemmed from a dispute between two groups, police said.

On Wednesday, a .45-caliber handgun that a 9-year-old boy in Bremerton had stashed in his backpack accidentally discharged, critically wounding an 8-year-old girl in their elementary-school classroom. Police said the boy found the gun at his mother's house and brought it to school because he wanted to run away from home.

Those were not the only incidents involving guns in the nation's schools in the first two months of the year.

In Las Vegas, authorities confiscated a 9-mm handgun from a 16-year-old student at a high school Jan. 30, and on Feb. 2, authorities stumbled upon a loaded .32-caliber handgun when they searched a teenage student at another high school who was suspected of stealing property from a classmate.

In Harper Woods, Mich., near Detroit, a 16-year-old student was showing off the 9-mm handgun he had brought to his high school when it went off. No one was injured, but a campus search found two more guns.

In Mesa, Ariz., on Jan. 6, a 7-year-old boy on a school bus inadvertently discharged a handgun hidden in his backpack. The single shot missed the 30 elementary students aboard for the ride home. Authorities said the youngster got the weapon from a closet at home and had it with him all day at school.

Twelve days later, in the same city, a 12-year-old boy was caught with a semiautomatic handgun and a loaded magazine at his junior-high school. The seventh-grader said he got the weapon from his grandfather's house and brought it to school because he felt threatened there and suicidal, police said.

Sheriff's deputies took a 12-year-old boy into custody Monday after witnesses reported he pointed a loaded .25-caliber pistol at a classmate standing in the lunch line at a rural junior-high school in Warren, Texas. Tyler County Sheriff David Hennigan says the seventh-grader apparently objected to comments the student made about a female classmate.

Experts say a focus on making schools more secure, training to recognize the signs of a potentially violent student and heightening efforts to curb bullying have been the positive legacy of the massacre at Columbine High School in Colorado. Two students there killed 12 classmates and a teacher on April 20, 1999.

Even so, the Columbine tragedy continues to fascinate some troubled students.

"Copycat threats are a real serious problem," said Dewey Cornell, director of the Virginia Youth Violence Project and a University of Virginia professor of education and school psychology.

"We see them every springtime around the anniversary of Columbine. We have kids who make copycat threats not only in the United States but in Europe,"Cornell said. "The dilemma for schools is how do you tell the difference between someone who is being foolish and someone who intends to commit a serious act of violence?"

Includes information from The Associated Press and The New York Times