January 9, 2018 Forest City, Iowa A man shot a pellet gun at a school bus full of children, shattering a window. No one was injured.
January 10, 2018 Denison, Texas A criminal justice club student picked up a loaded gun, belonging to an advisor, which the student thought was an unloaded training weapon. She then shot at a wall target, unintentionally firing a bullet, which went through the wall and broke a window. The advisor was a licensed peace officer permitted to carry a firearm on campus.
January 20, 2018 Winston-Salem, North Carolina A student was fatally shot at a party at 1 a.m. on the campus of Wake Forest University.
January 22, 2018 Italy, Texas A 16-year-old male student fired at a 15-year-old female classmate that he had briefly dated in the cafeteria of Italy High School. The gunman left the school immediately after opening fire and was arrested.
January 22, 2018 New Orleans, Louisiana Shots were fired from a truck in the parking lot of NET Charter High School, targeting a crowd of students during lunch time. One student was slightly injured, apparently from injuries unrelated to gunfire. One person was arrested in connection with the shooting.
January 23, 2018 Marshall County, Kentucky Marshall County High School shooting: A 15-year-old male student shot 16 people in the lobby at Marshall County High School and caused non-gunshot injuries to 4 others. Two 15-year-old students died: one killed at the scene, another died of wounds at Vanderbilt Medical Center.
January 25, 2018 Mobile, Alabama A disagreement between two 16-year-old students escalated when Jonah Neal pulled out a handgun. School administrators noticed the weapon and tried to calm him; Neal then fled across campus. He was pursued by staff until he fired the gun four or five times into the air. Nobody was injured. Neal was taken into custody and charged for multiple offenses, including possession of a weapon on school property.
January 31, 2018 Philadelphia, Pennsylvania A fight began in the school parking lot outside a basketball game, and the school went into lockdown after shots were fired. A 32-year-old male was transported by private vehicle to Nazareth Hospital with two gunshot wounds in his leg. He was transferred by helicopter to another hospital, but died from his injuries. Police announced that they are searching for an adult male suspect.
February 1, 2018 Los Angeles, California Two 15-year-old students, a boy and a girl, were shot and injured inside a classroom at Sal Castro Middle School, which shares a campus with Belmont High School. Three other people suffered injuries unrelated to gunfire. A 12-year-old girl was arrested and charged with negligent discharge of a firearm.
February 5, 2018 Oxon Hill, Maryland A student was taken to hospital after exiting Oxon Hill High School and going to speak to individuals in a vehicle who then attempted to rob, and subsequently shot and wounded him in the school's parking lot. Two other students were arrested and charged with attempted murder and robbery.
February 14, 2018 Parkland, Florida Marjory Stoneman Douglas ...l shooting: A 19-year-old former student whose behavior had led to his expulsion, began shooting students and staff members with a semi-automatic rifle at Marjory Stoneman Douglas High School after activating a fire alarm. 17 people were killed, and 14 others were injured. The suspect, Nikolas Cruz, blended in with the crowd of fleeing students and was arrested in a residential area of neighboring Coral Springs after walking away from the school. He was later charged with murder and attempted murder.
March 2, 2018 Mount Pleasant, Michigan Central Michigan University shooting: 19-year-old student James Eric Davis Jr. shot and killed his mother and father when they came to campus to take him home for spring break. After the shooting Davis fled and the campus was placed on lockdown. Around 15 hours later police arrested him and took him to a local hospital. The incident disrupted the travel plans of students and campus activities for several days. Davis was charged with two counts of murder and one count of unlawful possession of a firearm used to commit murder.
March 7, 2018 Birmingham, Alabama Huffman High School: One student was killed and another injured when shots were fired in the school building, prompting the school to go into lockdown shortly after the bell rang for school dismissal. Law enforcement originally labeled the shooting as "accidental". Subsequently, a 17-year-old male student was charged with manslaughter and will be charged as "being a certain person forbidden to possess a pistol". Although the school has metal detectors, they were not being used that day. School resource officers were onsite at the time of the shooting.
March 9, 2018 Lexington, Kentucky Frederick Douglass High School: A 16-year-old male student unintentionally shot himself with a gun he had smuggled into a classroom, sustaining an injury to his left thumb. Police announced they were charging him with wanton endangerment and possession of a weapon on school property. After the shooting, the school superintendent announced that stationary metal detectors would be installed and all students would be required to enter through them.
March 14, 2018 Birmingham, Alabama University of Alabama at Birmingham: A disgruntled employee entered the UAB Highlands Hospital on the campus of the University of Alabama at Birmingham and shot two hospital employees, fatally wounding one, on the second floor. The perpetrator then shot and fatally wounded himself.
March 20, 2018 Great Mills, Maryland Great Mills High School: School placed on lockdown after a shooting occurred in the morning. A 17-year-old male student, armed with a handgun, shot and fatally injured a female student (with whom he had a prior relationship) and wounded a male student. The student shot himself in the head, fatally, while the school resource officer simultaneously shot at him.
April 20, 2018 Ocala, Florida Forest High School: School evacuated after shooting occurred shortly before a national school walkout for gun control measures.
May 11, 2018 Palmdale, California Highland High School: 14-year-old former student fired a semiautomatic rifle shortly before classes were to begin. A 15-year-old was struck in the shoulder but went into surgery and was expected to recover fully. 
May 17, 2018 Dixon, Illinois Dixon High School: Student recently kicked off football team fires shots prior to graduation rehearsal. School resource officer shot suspect. Suspect had non-life threatening injuries. 
May 18, 2018 Santa Fe, Texas Santa Fe High School shooting: School was evacuated when fire alarms pulled at 7:45 am after students said they had heard gunshots. Shooter had a shotgun.
[Edited 5/18/18 12:45pm]