School Shootings In Which The Shooter Was A Former Student

I plan to update this list like my other ones. If you see any mistakes I made please let me know.

Townville Elementary School Shooting - Jesse Osborne: 14 year old Jesse Osborne shot 4 people at the school before being subdued. Jesse had killed his father before the shooting. A student who was shot died a few days later in the hospital. Osborne attended the school through 5th grade (Don't know if that means from kindergarten to 5th grade or just for 5th grade)

Sandy Hook Elementary School Shooting - Adam Lanza: 20 year old Adam Lanza killed his mother, then drove to Sandy Hook Elementary School where he shot and killed 20 children and 6 staff members before killing himself. Lanza attended Sandy Hook from 1998 (1st grade) to 2002 for 5th grade

Aztec High School Shooting - William Atchison: 21 year old William Atchison entered the school disguised as a student and loaded his weapon in a boys bathroom. He then killed 2 students and fired at stuff in the hallways before killing himself. Atchison was a former student at the school but dropped out twice (2010 and 2012). He never earned his diploma and instead got a GED. He had also been suspended in 2012 (the same year he dropped out a second time) for writing the Columbine High School Massacre timeline on a white board.

Erfurt School Massacre - Robert Steinhäuser: On April 26th, 2002, 19 year old Robert Steinhäuser told his mother he was going to the Gutenberg-Gymnasium to take his exams, but instead he packed up a pump action shotgun and a handgun with hundreds of rounds of ammo in a sports bag along with black clothing, got on a bus, asking the driver to take him to the school. He arrived and entered a mens bathroom where he loaded his handgun (his shotgun failed to operate) put on the clothing, and proceeded to kill 13 staff members, 2 students, and a police officer before killing himself. The then-18 year old Steinhäuser was expelled from the school in October of 2001 after he had been caught forging doctors notes to excuse his multiple day truancy. The school however did not report his expulsion to his parents, and Robert was able to keep this a secret from his family.

Winnenden School Shooting - Tim Kretschmer: 17 Year old Tim Kretschmer stole his fathers 9mm handgun and more than 300 rounds of ammunition and went to the Albertville-Realschule in Winnenden. Kretschmer entered the school and shot and killed 9 students and 3 teachers before escaping. He then shot and killed a gardener near a hospital before carjacking a minivan and ordering the driver to take him to the nearby town of Wendlingen. Upon arriving, the driver escaped the car and ran towards a police patrol car. Kretschmer did the same and ran towards an industrial area of the town and entering a car dealership where he killed 2 people before police engaged Tim in a shootout, hitting him in each leg. Kretschmer then left the dealership running from the cops, he managed to injure 2 police officers in a police car in the process and escaped to a parking lot, continuing the shootout before he ultimately committed suicide. Kretschmer graduated from the school in 2008 and at the time of the shooting he was attending a commercial school to prepare for a apprenticeship in business.

Marjory Stoneman Douglas High School Shooting - Nikolas Cruz: 19 year old Nikolas Cruz arrived at MSDHS via Uber with a Smith & Wesson M&P15 rifle in a rifle case and multiple rounds of ammo and headed towards Building 12, a three story building for freshmen classes. He took out the rifle on a staircase and told a student to "Get out of here" before pulling a fire alarm and opening fire, killing 14 students and 3 staff members before his rifle jammed and escaped on foot. He was arrested in a neighborhood an hour later in a neighborhood in Coral Springs Florida. Cruz was expelled from the high school in 2017 for disciplinary reasons and at the time of the massacre he was in a GED program and working at a Dollar Tree.

Emsdetten School Shooting - Sebastian Bosse: On November 20th 2006, 18 year old Bastian Bosse arrived at the Geschwister Scholl-Schule in a rental car wearing a black trench coat, black clothing, a gas mask and armed with multiple weapons including 2 sawed off rifles, 2 pistols, a knife and machete, homemade bombs including smoke bombs, molotov cocktails and incendiary grenades, and pipe bombs. He went into the schoolyard and shot and injured a janitor and hit a female teacher in the face with a smoke bomb. He then went inside the school and shot and wounded 4 students. He then threw smoke bombs into classrooms and other areas of the school, which resulted in smoke inhalation to students and responding police officers. Bosse then went up to the second and shot himself in an empty classroom. Conflicting news sources suggest anywhere between 5 and 9 people were shot as opposed to just 5. Bosse graduated from the school the same year and was reportdedly a victim of bullying since 1st grade.

Guilherme Taucci Monteiro and Luiz Henrique de Castro, perpetrators of the Suzano school shooting (8 killed, 11 wounded), were both former students.

Northern Illinois University shooting: On February 14th, 2008, 27 year old Steven Kazmierczak entered a large auditorium-style lecture hall in Cole Hall where an oceanography class was in session with approximately 120 students present. He opened the door with such extreme force that many witnesses described him as "kicking the door in", entering at the extreme southwest corner, near the stage in front of the classroom, and opened fire on the crowd of students with a shotgun. He next shot at the instructor, who was standing on the east side of the stage. After shooting all six shotgun rounds, Kazmierczak fired on the room's remaining occupants with a 9mm pistol, firing a total of approximately 50 rounds. He was reported to have walked up and down the west aisle and directly in front of or on the stage, firing at people as he went. He shot and killed himself before police reached the room. In the end, 6 people were dead (including Kazmierczak) and 21 were injured.

18 year old Alvaro Castillo opened fire at Orange High School in 2006 after having shot his father multiple times, he ended up injuring two students but his gun jammed and he was then subdued. He showed excessive admiration for Columbine and Eric Harris. He is currently serving a life sentence in a North Carolina prison.

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On November 7th 1994, a 37 year old named Keith Ledeger went to his former middle school with a 12 gauge shotgun and opened fire, killing a custodian and wounding 4 others.

Patrick Purdy - Cleveland Elementary School shooting

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Patrick Edward Purdy did not come to the grounds of Cleveland Elementary School as a complete stranger. The gunman who raked the school’s crowded playground with 110 rounds of rifle fire, killing five children and wounding 29 others and a teacher before taking his own life, had himself completed kindergarten through second grade at Cleveland, officials said Wednesday.

The significance of the discovery was not immediately clear. School records yielded nothing remarkable about Purdy’s experience there, only the normal academic promotions and mandatory vaccinations, but the connection did indicate that the midday attack Tuesday was not wholly random.

On January 16th, 2002, 43-year-old former student Peter Odighizuwa opened fire at the Appalachian School of Law, killing three people and injuring three others before being subdued.

Salvador Ramos attended Robb Elementary School in the 4th grade and ended his rampage in the same classroom he attended while there.