CENTENNIAL, Colo. — After Friday’s shooting at Arapahoe High School, many Coloradans have been wondering whether school attacks are especially common in our state, or if it simply seems that way.

The following partial list of random school violence incidents compiled by CNN helps shed some light on the facts.

California, which obviously contains many more schools and students than does Colorado, has seen more incidences of school violence since 1927.  But perhaps most surprising is the revelation that gun violence committed by the victims of bullying can be tracked at least as far back as 1978.

Here is a list of incidences of random elementary, middle and high school (excludes colleges and universities) violence with fatalities, from 1927 to the present. This list does NOT include suicides, gang-related incidents, or deaths resulting from interpersonal conflicts.

• December 13, 2013 – A student opens fire inside Arapahoe High School in Centennial, Colorado, injuring one person and then killing himself.
• October 21, 2013 – Sparks Middle School – Sparks, Nevada. An unidentified student takes his parent’s hand-gun to school and shoots three, injuring two 12-year-old male students and killing Mike Landsberry, a teacher and Marine veteran. He then kills himself.
• December 14, 2012 – Sandy Hook Elementary School – Newtown, Connecticut. Adam Lanza, 20, guns down 20 children, ages 6 and 7, and six adults, school staff and faculty, before turning the gun on himself. Investigating police later find Nancy Lanza, Adam’s mother, dead from a gunshot wound. The final count is 28 dead, including the shooter.
• February 27, 2012 – A shooting occurs at Chardon High School in Ohio. Student Daniel Parmertor, 16, is killed and four others wounded when student T.J. Lane, 17, opens fire in the school. On February 28, Demetrius Hewlin, 16, dies from his wounds and Russell King Jr., 17, is declared brain dead. On March 1 Lane is charged with three counts of aggravated murder, two of attempted aggravated murder and one of felonious assault. – February 26, 2013 – Pleads guilty to three counts of attempted aggravated murder, two counts of attempted murder and a one count of felonious assault. As part of the plea, the death penalty is removed. – March 19, 2013 – Lane is sentenced to life in prison. He wore a white T-shirt with the word “killer” written on it to the sentencing hearing, and didn’t allow his attorneys to present evidence on his behalf.
• January 5, 2011 – Millard South High School, Omaha, Nebraska. 17-year-old Robert Butler Jr. opens fire on principal Curtis Case and vice principal Vicki Kasper. Butler then kills himself about a mile from the school. Vice principal Kasper later died at the hospital.
• February 5, 2010 – Discovery Middle School, Madison, Alabama. 14-year-old Todd Brown dies after being shot in the head in a school hallway. A fellow ninth-grader is the suspected shooter and is taken into custody.
• October 16, 2009 – Carolina Forest High School, Conway, South Carolina. A 16-year-old student is shot and killed by a police officer after allegedly pulling a knife and stabbing the officer.
• September 23, 2009 – John Tyler High School, Tyler, Texas. A 16-year-old student is taken into custody for stabbing and killing high school teacher Todd R. Henry.
• September 15, 2009 – Coral Gables Senior High School, Coral Gables, Florida. 17-year-old Andy Jesus Rodriguez fatally stabs 17-year-old sophomore Juan Carlos Rivera during a fight.
• August 21, 2008 – Central High School, Knoxville, Tennessee. An unnamed teen shoots and kills another teen. The suspect is arrested by police.
• January 3, 2007 – Henry Foss High School, Tacoma, Washington. Student Douglas Chanthabouly, 18, fatally shoots another student, Samnang Kok, 17. Chanthabouly has been taken into custody and charged with first-degree murder.
• October 2, 2006 – Georgetown Amish School, Nickel Mines, Pennsylvania. 32-year-old Charles Roberts IV goes to a small Amish school and takes at least 11 girls hostage. Five girls were killed and six others wounded. Roberts then killed himself.
• September 29, 2006 – Weston High School, Cazenovia, Wisconsin. 15-year-old Eric Hainstock goes to school armed with a shotgun and a handgun. After a struggle with the school janitor, Hainstock shoots and kills the school principal. He is convicted of murder in August 2007 and sentenced to life in prison.
• September 27, 2006 – Platte Canyon High School, Bailey, Colorado. 54-year-old Duane Morrison takes six female students hostage. When SWAT teams enter the school, Morrison shoots 16-year-old Emily Keyes. Morrison then kills himself. Keyes later died at the hospital.
• November 8, 2005 – Campbell County Comprehensive High School, Jacksboro, Tennessee. A 15-year-old student opens fire on a principal and two assistant principals, killing one of them and critically wounding another, authorities said.
• March 21, 2005 – Red Lake High School, Red Lake, Minnesota. 16-year-old Jeff Weise kills his grandfather and another adult, four fellow students, a teacher and a security officer. He then killed himself.
• February 3, 2004 – Southwood Middle School – Palmetto Bay, Florida. 14-year-old Michael Hernandez slashes the throat of 14-year-old Jaime Rodrigo Gough.
• September 24, 2003 – Rocori High School – Cold Spring, Minnesota. 15-year-old Jason McLaughlin shoots and kills 17-year old Aaron Rollins and critically injures another student. The second student died in October. McLaughlin has been charged with second-degree murder.
• April 24, 2003 – Red Lion Area Junior High School – Red Lion, Pennsylvania. 14-year-old James Sheets brings a revolver to school and kills his principal, Eugene Segro, and then himself.
• December 5, 2001 – Springfield High School – Springfield, Massachusetts. At a high school for troubled teens, 17-year-old Corey Ramos stabs to death Reverend Theodore Brown, a counselor at the school. In 2003, Ramos is sentenced to life in prison.
• March 5, 2001 – Santana High School – Santee, California. 15-year-old Charles “Andy” Williams kills two classmates, a 14-year-old and a 17-year-old, and injures 13. Williams is sentenced in 2002 to at least 50 years in prison.
• May 26, 2000 – Lake Worth Community Middle School – Lake Worth, Florida. 13-year-old Nathaniel Brazill, after being sent home for misbehaving, returns to school and shoots and kills his teacher Barry Grunow. Brazill is sentenced to 28 years in prison.
• February 29, 2000 – Buell Elementary School – Mount Morris Township, Michigan. An unnamed six-year-old boy shoots and kills a six-year-old playmate, Kayla Rolland, at school. He is removed from his mother’s custody and put up for adoption.
• November 19, 1999 – Deming Middle School – Deming, New Mexico. 12-year -old Victor Cordova shoots and kills a 13-year-old classmate. He is sentenced to two years in juvenile detention.
• April 20, 1999 – Columbine High School – Littleton, Colorado. 18-year-old Eric Harris and 17-year-old Dylan Klebold kill 12 fellow students and one teacher before committing suicide in the school library.
• May 21, 1998 – Thurston High School – Springfield, Oregon. After killing his parents the previous day, 15-year-old Kip Kinkel returns to Thurston High armed with a rifle. He kills two students in the school cafeteria, a 16 and a 17-year-old. He is sentenced to 112 years in prison.
• April 24, 1998 – James Parker Middle School – Edinboro, Pennsylvania. 14-year-old Andrew Wurst shoots and kills science teacher John Gillette at a school dance. He is sentenced to serve between 30 and 60 years.
• March 24, 1998 – Westside Middle School – Jonesboro, Arkansas. 11-year-old Andrew Golden and 13-year-old Mitchell Johnson ambush fellow students and their teachers, killing five. Johnson is incarcerated in a youth facility and released on his 21st birthday August 11, 2005. Golden is released on his 21st birthday, May 25, 2007.
• December 1, 1997 – Heath High School – West Paducah, Kentucky. 14-year-old Michael Carneal opens fire on a school prayer group, killing three girls, who were 14, 15, and 17. He is serving life in prison.
• October 1, 1997 – Pearl High School – Pearl, Mississippi. After killing his mother at home, 16-year-old Luke Woodham arrives at school and shoots two classmates. Woodham is serving three life sentences plus 140 years.
• February 19, 1997 – Bethel High School – Bethel, Alaska. 16-year-old Evan Ramsey uses a shotgun stolen from his foster home to kill a 15-year-old student and the school principal. He is currently serving a term of 210 years.
• September 25, 1996 – Dekalb Alternative School – Decatur, Georgia. 16-year-old David Dubose Jr. shoots and kills English teacher Horace Morgan on the steps of the school. Dubose was found not guilty by reason of insanity and committed indefinitely to a state mental hospital.
• February 2, 1996 – Frontier Junior High School – Moses Lake, Washington. 14-year-old Barry Loukaitis takes a rifle to school and kills two classmates and a teacher. He was sentenced to life in prison.
• January 19, 1996 – Winston Education Center – Washington, D.C. Two masked gunmen kill 14-year-old Damion Blocker in a stairwell. 16-year-old shooter Darrick Evans was given a sentence of 41 years to life in prison.
• November 15, 1995 – Richland High School – Lynnville, Tennessee. 17-year-old Jamie Rouse kills a business teacher and a 16-year-old student. Rouse is serving a life sentence.
• October 12, 1995 – Blackville-Hilda High School – Blackville, South Carolina. 15-year-old Toby Sincino kills a teacher and then himself.
• November 7, 1994 – Wickliffe Middle School – Wickliffe, Ohio. 37-year-old drifter Keith Ledeger shoots and kills school custodian Peter Christopher and injures three others. Ledeger is sentenced to life in prison.
• April 12, 1994 – Margaret Leary Elementary School – Butte, Montana. 10-year-old Jason Osmanson, teased because his parents have AIDS, shoots and kills an 11-year-old on the school playground. Osmanson is sent to a private residential treatment center.
• February 1, 1994 – Valley View Junior High School – Simi Valley, California. 13-year-old Philip Hernandez stabs to death a 14-year-old student in a school hallway. Hernandez is sentenced to four years in a California Youth Authority prison.
• December 1, 1993 – Wauwatosa West High School – Wauwatosa, Wisconsin. 21-year-old former student Leonard McDowell returns to his high school and kills associate principal Dale Breitlow. He is sentenced to life in prison.
• May 24, 1993 – Upper Perkiomen High School – Pennsburg, Pennsylvania. 15-year-old student Jason Smith kills another student who had bullied him. He is sentenced to between 12 and 25 years in prison.
• April 15, 1993 – Ford Middle School – Acushnet, Massachusetts. 44-year-old David Taber invades a middle school and takes three hostages. He later shoots and kills school nurse Carol Day. He is found not guilty of the murder by reason of insanity.
• April 12, 1993 – Dartmouth High School – Dartmouth, Massachusetts. 16-year-old Jason Robinson is stabbed to death in his social studies class by three teenage attackers who invade the classroom.
• January 18, 1993 – East Carter High School – Grayson, Kentucky. 17-year-old student Scott Pennington shoots and kills a teacher and custodian. He is sentenced to life in prison.
• May 1, 1992 – Lindhurst High School – Olivehurst, California. 20-year-old dropout Eric Houston returns to his high school and kills a former teacher and three students. Houston is sentenced to death.
• February 26, 1992 – Thomas Jefferson High School – Brooklyn, New York. A 15-year-old shoots and kills two other students. The shooter, Kahlil Sumpter, was sentenced in 1993 to between 6 2/3 and 20 years in prison and is released in 1998.
• November 25, 1991 – Thomas Jefferson High School – Brooklyn, New York. A stray bullet kills a 16-year-old student during an argument between two other teens. Shooter Jason Bentley, 14, is sentenced in 1992 to three to nine years in prison.
• January 17, 1989 – Cleveland Elementary School – Stockton, California. 24-year-old drifter Patrick Purdy uses an AK-47 to kill five children on an elementary school playground. He then takes his own life.
• December 16, 1988 – Atlantic Shores Christian School – Virginia Beach, Virginia. 16-year-old Nicholas Elliot shoots and kills teacher Karen Farley. Elliott is sentenced to life in prison with the possibility of parole.
• September 26, 1988 – Oakland Elementary School – Greenwood, South Carolina. 19-year-old James Wilson, copying the Winnetka, Illinois murders, kills 8-year-olds Tequila Thomas and Shequila Bradley in their school cafeteria. Wilson’s death sentence is overturned in January 2003.
• May 20, 1988 – Hubbard Woods Elementary School – Winnetka, Illinois. 30-year-old Laurie Dann invades an elementary school and kills an 8-year-old boy. She injures six other people before taking her own life.
• February 11, 1988 – Pinellas Park High School – Largo, Florida. Two 15-year-olds with stolen weapons, Jason McCoy and Jason Harless, shoot and kill assistant principal Richard Allen. McCoy serves two years in prison and Harless serves eight.
• March 2, 1987 – Dekalb High School – Dekalb, Missouri. 12-year-old Nathan Faris, who was teased about being overweight, shoots 13-year-old Timothy Perrin and then takes his own life.
• December 4, 1986 – Fergus High School – Lewistown, Montana. 14-year-old Kristofer Hans shoots and kills substitute teacher Henrietta Smith. He is sentenced to 206 years in prison in 1988.
• May 16, 1986 – Cokeville Elementary School – Cokeville, Wyoming. A couple in their 40s, David and Doris Young, take over an elementary school with a bomb and hold 150 children and adults hostage, demanding $300 million in ransom. The bomb accidentally detonates, setting the school on fire. Investigators later determine that during the fire David Young shot his wife and then killed himself. 74 people were injured in the fire.
• January 21, 1985 – Goddard Junior High School – Goddard, Kansas. 14-year-old James Kearbey shoots and kills Principal Jim McGee. Kearbey spent seven years in juvenile detention and was released at the age of 21. On October 31, 2001, Kearbey was involved in a six-hour standoff with Wichita, KS police. No injuries resulted and Kearbey was later acquitted of aggravated assault on a police officer.
• February 24, 1984 – 49th Street School – Los Angeles, California. Sniper Tyrone Mitchell shoots at children on an elementary school playground, killing one and injuring 11. He later takes his own life.
• January 20, 1983 – Parkway South Junior High – St. Louis, Missouri. An unnamed 14-year-old shoots and kills another student before turning the gun on himself.
• March 19, 1982 – Valley High School – Las Vegas, Nevada. 17-year-old Pat Lizotte shoots and kills psychology teacher Clarence Piggott during class. Lizotte is sentenced to life in prison.
• January 29, 1979 – Grover Cleveland Elementary – San Diego, California. 16-year-old Brenda Spencer opens fire on a school across from her home, killing the principal and janitor.
• May 18, 1978 – Murchison Junior High School – Austin, Texas. 13-year-old John Christian shoots and kills his English teacher Wilbur Grayson, during class. The shooter is the son of George Christian, press secretary to President Lyndon Johnson from 1967 to 1969. After time in a psychiatric hospital, Christian attends high school in the Dallas area.
• February 22, 1978 – Everett High School – Lansing, Michigan. 15-year-old Roger Needham kills another student who had bullied him. After four years in juvenile detention, Needham is released. He later earned a PhD in math and worked as a professor in Missouri and New York.
• March 18, 1975 – Sumner High School – St. Louis, Missouri. 16-year-old Stephen Goods, a bystander, is shot and killed during a fight between other teens.
• December 30, 1974 – Olean High School – Olean, New York. Honors student Anthony Barbaro kills a school janitor and two passers-by. Barbaro later kills himself while awaiting trial.
• November 12, 1966 – In Mesa, Arizona, 18-year-old high school student Robert Smith kills five people at a local beauty college. He is sentenced to life in prison.
• October 5, 1966 – Grand Rapids High School – Grand Rapids, Minnesota. 15-year-old David Black injures another student before killing teacher Forrest Willey.
• September 15, 1959 – Edgar Allen Poe Elementary – Houston, Texas. Convict Paul Orgeron explodes a suitcase of dynamite on a school playground, killing himself, two adults and three children.
• May 18, 1927 – Bath Consolidated Schoolhouse – Bath, Michigan. Farmer Andrew Kehoe sets off two explosions at the school, killing himself, six adults and 38 children.

CNN contributed to this article.