The purpose of the letter bombs -- which resulted in minimal casualty -- was to send a message.
1	The	the	DET	DT	Definite=Def|PronType=Art	2	det	2:det	_
2	purpose	purpose	NOUN	NN	Number=Sing	16	nsubj:outer	16:nsubj:outer	_
3	of	of	ADP	IN	_	6	case	6:case	_
4	the	the	DET	DT	Definite=Def|PronType=Art	6	det	6:det	_
5	letter	letter	NOUN	NN	Number=Sing	6	compound	6:compound	_
6	bombs	bomb	NOUN	NNS	Number=Plur	2	nmod	2:nmod:of|9:nsubj	_
7	--	--	PUNCT	,	_	6	punct	6:punct	_
8	which	which	PRON	WDT	PronType=Rel	9	nsubj	6:ref	_
9	resulted	result	VERB	VBD	Mood=Ind|Number=Plur|Person=3|Tense=Past|VerbForm=Fin	6	acl:relcl	6:acl:relcl	_
10	in	in	ADP	IN	_	12	case	12:case	_
11	minimal	minimal	ADJ	JJ	Degree=Pos	12	amod	12:amod	_
12	casualty	casualty	NOUN	NN	Number=Sing	9	obl	9:obl:in	_
13	--	--	PUNCT	,	_	16	punct	16:punct	_
14	was	be	AUX	VBD	Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin	16	cop	16:cop	_
15	to	to	PART	TO	_	16	mark	16:mark	_
16	send	send	VERB	VB	VerbForm=Inf	0	root	0:root	_
17	a	a	DET	DT	Definite=Ind|PronType=Art	18	det	18:det	_
18	message	message	NOUN	NN	Number=Sing	16	obj	16:obj	SpaceAfter=No
19	.	.	PUNCT	.	_	16	punct	16:punct	_
