Table 9. Perpetrator characteristics by type of school shooting, 1990-2012.

Perpetrator characteristics			Type of school shooting incident
			Random/rampage		Targeted		Other		Total
Total perpetrators			27		152		51		230
Mean age			22.6		24.4		16.9		23.0
Age group			No.	%	No.	%	No.	%	No.	%
	<18 years		9	33.3	52	34.2	13	25.5	74	32.2
	18-24 years		11	40.8	29	19.1	11	21.6	51	22.2
	25-34 years		2	7.4	15	9.9	0	0.0	17	7.4
	>35 years		3	11.1	23	15.1	0	0.0	26	11.3
	Missing		2	7.4	33	21.7	27	52.9	62	26.9
Gender			No.	%	No.	%	No.	%	No.	%
	Male		25	92.6	121	79.6	22	43.1	168	73.0
	Female		2	7.4	3	2.0	1	2.0	6	2.6
	Missing		0	0.0	28	18.4	28	54.9	56	24.4
Perpetrator relation to school
	Current Student		11	40.8	67	44.1	16	31.4	94	40.9
	Former Student		6	22.2	8	5.2	0	0.0	14	6.1
	Student from Other School		3	11.1	4	2.6	3	5.9	10	4.3
	Employee/Teacher		0	0.0	12	7.9	0	0.0	12	5.2
	Related to Student or School Employee		0	0.0	8	5.3	0	0.0	8	3.5
	Boy/Girlfriend or Romantic Interest of Student or School Employee or Parent of Student		0	0.0	7	4.6	0	0.0	7	3.0
	Unknown/Other		7	25.9	46	30.3	32	62.7	85	37.0
Perpetrator suicide
	Committed Suicide		10	37.0	22	14.5	1	2.0	33	14.3
	No Suicide		17	63.0	130	85.5	50	98.0	197	85.7