WIXLIB

SUPPLEMENTARY APPENDIXSCHOOL SHOOTINGS IN THE US FROM 2013-2014Table of ContentsSupplementary Table 1: Descriptive characteristics of school shooting incidents by state,2013-2015 . 2Supplementary Table 2: Sensitivity analysis of association between state gun laws, statemental health expenditure and school shooting incidents among incidents with no reportedmortality. . 13Supplementary Table 3: Association between state mental health expenditure, K-12expenditure and school shooting incidents. 14Supplementary Appendix 1: Inclusion and exclusion criteria. 15Supplementary Appendix 2: Data collection methodology . 16Supplementary Appendix 3: State-specific description of background check laws during2013, 2014 and 2015. . 191

Supplementary Table 1: Descriptive characteristics of school shooting incidents by state, 2013-2015School123456789102013ApostolicRevival CenterChristianSchoolTaft UnionHigh SchoolStevensInstitute ofBusiness &ArtsHazardCommunityand TechnicalCollegeChicago StateUniversityLone StarCollege NorthHarris CampusPrice olUniversity ofIntentionalShooterCommittedSuicide(1 Yes,0 No)ShooterDead(1 Yes,0 No)Total DeadVictims(Students non-students,excludingshooter)Total nonfatally shotstudents(excludingshooter)Total nonfatally shotnon-students(excludingshooter)Total nonfatallyinjuredstudents(injury butnot shot)Total nonfatallyinjured nonstudents(injury butnot 100100010001000100011010110000000002

11121314151617181920212223Central FloridaDavidsonMiddle SchoolNew RiverCommunityCollegeElizabeth nCollegeLa Salle HighSchoolSanta MonicaCollegeAlexander W.DreyfoosSchool of theArtsRonald SchoolNorth PanolaHigh SchoolCarver HighSchoolSavannah 00010001000100100003

242526272829303132333435363738NewGloucesterHigh SchoolAgapeChristianAcademyLanier HighSchoolSparks MiddleSchoolAlgonaHigh/MiddleSchoolNorth CarolinaA&T StateUniversityStephensonHigh SchoolSouth DakotaSchool ofMines &TechnologyWest OrangeHigh SchoolArapahoe HighSchoolEdison HighSchoolLibertyTechnologyMagnet HSBerrendoMiddle SchoolMartin LutherKing Jr. 0010001000200001000000020000004

394041424344454647484950515253Valley CharterHSWidenerUniversityPurdueUniversitySouth ar ChavezHigh SchoolNorth HighSchoolBend HighSchoolSalisbury HighSchoolBrush nielCollegeUniversity ofWisconsin –OshkoshUniversity ofDelawareKent 000100000000000000000000000000000005

54555657585960616263646566676869East EnglishVillagePreparatoryAcademySt. MaryCatholicSchoolProvo HighSchoolIowa lementarySchoolPaine CollegePaine k StreetSchoolSeattle PacificUniversityReynolds HighSchoolKelly HighSchoolUniversity ofMiamiHeather RidgeHigh 00111101000001000010000000100000006

aho StateUniversitySavannah StateUniversityGreenwoodLakes MiddleSchoolWestbrookElementarySchoolJoel C. HarrisAcademyTennesseeStateUniversityIndiana StateUniversityAlbermarleHigh SchoolFern HighSchoolLangstonHughes HighSchoolElizabeth nUniversityA. MaceoWalker 001000000000000000000010007

ck HighSchoolFlorida StateUniversitySt. John’sCollegeRogers entarySchoolWisconsinLutheran HighSchoolVanguardHigh SchoolWilliamsonHigh SchoolRoyal LiveOaks AcademyHand in ityFrederick HighSchoolUniversity ofSouth 000010002000111100008

y ofGeorgiaLawsonElementarySchoolTenaya ationalCollegeLane CollegeCommunityCollege ofBeaver Seguin HighSchoolDelaware StateUniversityJohnson C.SmithUniversityRuthe DeskinElementarySchoolNorthThurston 00100000000000000000009

wElementarySchoolUtah ValleyUniveristyConyersMiddle SchoolCorona del SolHigh SchoolRobinson ty SchoolSouth MaconElementarySchoolFort CalhounElementarySchoolCoppellMiddle SchoolEastElolfElementarySchoolUniversity ofFloridaWichita StateParadise 00000010

lementarySchoolTexasSouthernUniversitySavannah StateUniversitySacramentoCity CollegeNorthsideHigh SchoolDelta StateUniversityCentralElementarySchoolMontana Techof theUniversity ofMontanaHarrisburgHigh SchoolUmpquaCommunityCollegeUniversityCity 00010000100110000111300000011

ersityUniversity ofSouth FloridaLangstonUniversityWagner HighSchoolTennesseeStateUniversityEd WhiteMiddle SchoolNorth CarolinaCentralUniversityWinstonSalem StateUniversityVereen SchoolLecanto HighSchoolSulphur RockMagnet SchoolOhio StateUniversityLane 000100000110110100100000000000012

Supplementary Table 2: Sensitivity analysis of association between state gun laws, state mental healthexpenditure and school shooting incidents among incidents with no reported mortality.Crude IRR (95% CI) pIncidence rates by year, n (per 10 million population)20132014201510924 (0.76)42 (1.32)43 (1.34)Background checks for firearm purchaseBackground checks for ammunition purchase0.55 (0.34-0.90)0.08 (0.01-0.49)0.0170.007Urbanicity (% of population in urban areas), 2010Log of Mental health per capita expenditure in , 2013Log of Per capita expenditure on K-12 education, 20130.97 (0.95-0.99)0.58 (0.35-0.99)0.09 (0.02-0.40)0.0050.0470.001Crude incidence rate ratios (IRR) and 95% confidence intervals (95% CI) for each covariate were derived from separate negativebinomial regression models with log of population as an offset, cluster on state, and adjusted for year as a linear term. Backgroundcheck for firearm purchase and ammunition purchase was obtained for 2013, 2014 and 2014.13

Supplementary Table 3: Association between state mental health expenditure, K-12 expenditure and schoolshooting incidents.Log of Mental health per capita expenditure in , 2013 72.44 72.44- 99.1 99.1- 160.5 160.5Log of Per capita expenditure on K-12 education, 2013 1.35 1.36- 1.65 1.66- 2.01 2.02Crude IRR (95% CI) p0.014Reference1.07 (0.61-1.86)0.52 (0.30-0.89)0.42 (0.20-0.89)0.001Reference0.65 (0.35-1.21)0.60 (0.42-0.87)0.19 (0.07-0.50)14

Supplementary Appendix 1: Inclusion and exclusion criteriaInclusion criteria:Firearm discharged within the school campus, either within the buildings or on school grounds (including school/college parking lot).Separate incidents of school shootings within the same school were considered as individual events.Exclusion criteria:1.Firearm was present, but not discharged2.Firearm discharge occurred outside or out the bounds of the school campus and NOT within the school campus.15

Supplementary Appendix 2: Data collection methodologyWe used LexisNexis using keywords such as [(“school” OR “college” OR “university”) AND (“shooting” OR “gun” OR “shot”)]within a time period between 01/01/2013 to 12/31/2015. We obtained 941 hits and each one went preliminary screening whether itwas pertaining to school shooting. We then applied our inclusion and exclusion criteria to finalize 154 incidents during this timeperiod. We then compared our list to the EVERYTOWN school shooting list (160) and found that we have excluded 9 incidentsduring this time period and had 3 additional incidents. Those incidents that we had not listed were then assessed and checked forreasons for exclusion. Below we list the reason for exclusion and inclusion.Everytown defined their first inclusion criterion: that a firearm must have been discharged. Their second criterion was that the firearmhad to have been discharged or bullets must impact on the school’s campus. After verifying several media reports of each incidentreported in LexisNexis, we excluded nine (9) incidents for not meeting our inclusion/exclusion criteria. We also identified 3 additionalincidents not included in the Everytown report school-shootings/)1.2/7/2013- Indian River State College in Fort Pierce, Florida was excluded as a shooting occurred off campus and thesuspect then drove onto the campus. As the discharge of the firearm was not on campus and no bullets ever hit campus.2.2/27/2013- Grady High School in Atlanta, Georgia was excluded as the shooting occurred on the corner of a street next tothe football stadium. Though the school responded as if it were on campus, technically this was outside of the boundary ofthe school.16

3.5/3/2013- University of Southern Mississippi in Hattiesburg, MS was excluded since the shooting of the three studentsoccurred off-campus.4.8/15/2013- Northwest High School in Clarksville, Tennessee was excluded as only a body was found on the campuswithout any evidence of where the shooting occurred and therefore cannot be certified to meet the inclusion criteria.5.1/28/2014- Grambling State University in Grambling, Louisiana was excluded as no corroborating sources could be foundand therefore the authors could not independently verify the inclusion criteria.6.3/7/2014- Madison High School in Tallulah, Louisiana was excluded as the shooting actually occurred in a park across thestreet from the school and therefore the firearm was not discharged on actual school property.7.3/30/2014- Savannah State University in Savannah, Georgia was excluded as no corroborating sources could be found andtherefore the authors could not independently verify the inclusion criteria.8.3/9/2015- Northwest Passage Alternative High School in Coon Rapids, Minnesota was excluded because the shootingoccurred in an apartment complex near the school thus being excluded upon failure to meet the inclusion criterion of thedischarge occurring on campus.9.4/19/2015- Delaware State University, Dover, DE was excluded since it occurred just off-campus, in a university-runhousing complex. This was a shooting that occurred 5 hours after an earlier shooting.The additional events were17

1.09/24/2014- Joel C. Harris Academy in San Antonio, Texas. The gun fired while it was in a backpack of a 12-year old boy.One report also mentions that the gun was loaded with blanks. There were no injuries.2.1/23/2015- Royal Live Oaks Academy in Hardeeville, South Carolina. A male juvenile discharged a firearm into the air inthe school property and fled.3.3/30/2015- American International College in Springfield, Massachusetts was included because the gunfire of at least 10shots fired in the street shot through windows of the school into a room where students were eating lunch.18

Supplementary Appendix 3: State-specific description of background check laws during 2013, 2014 and2015.ALABAMA:Did not have background check laws for firearm purchase or ammunition purchase during 2013, 2014 or 2015.ALASKA:Did not have background check laws for firearm purchase or ammunition purchase during 2013, 2014 or 2015.ARIZONA:Did not have background check laws for firearm purchase or ammunition purchase during 2013, 2014 or 2015.ARKANSAS:Did not have background check laws for firearm purchase or ammunition purchase during 2013, 2014 or 2015.CALIFORNIA:Had background check laws for all types of firearm purchase during 2013, 2014 and 2015.Did not have back ground checks for ammunition purchase during 2013, 2014 or 2015.COLORADO:Had background check laws for firearm purchase at gun shows only (C.R.S. § 12-26.1-101) until July 2013. Background check lawtook effect in July 2013 (Colo. Rev. Stat. § 18-12-112), therefore reported as present in 2014 and 2015.Did not have back ground checks for ammunition purchase during 2013, 2014 or 2015.CONNECTICUT:Background check law for firearm purchase was extended only towards handgun purchase (Conn. Gen. Stat. §§ 29-33, 29-36f, 2936g), while purchase of long guns did not require background checks in 2013.Background check law for firearm purchase was extended only towards handgun purchase (Conn. Gen. Stat. §§ 29-33, 29-36f, 2936g), while background checks for long gun purchases took effect in April 2014 (Conn. Gen. Stat. §§ 29-37a, 29-37p, 29-37q) in2014. We record this as handgun purchase only in year 2014.19