First, the nature of such an investigation is that we lack sufficient information to second-guess (or even know) what the FBI is doing.
1	First	first	ADV	RB	NumType=Ord	12	advmod	12:advmod	SpaceAfter=No
2	,	,	PUNCT	,	_	12	punct	12:punct	_
3	the	the	DET	DT	Definite=Def|PronType=Art	4	det	4:det	_
4	nature	nature	NOUN	NN	Number=Sing	12	nsubj:outer	12:nsubj:outer	_
5	of	of	ADP	IN	_	8	case	8:case	_
6	such	such	DET	PDT	_	8	det:predet	8:det:predet	_
7	an	a	DET	DT	Definite=Ind|PronType=Art	8	det	8:det	_
8	investigation	investigation	NOUN	NN	Number=Sing	4	nmod	4:nmod:of	_
9	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	12	cop	12:cop	_
10	that	that	SCONJ	IN	_	12	mark	12:mark	_
11	we	we	PRON	PRP	Case=Nom|Number=Plur|Person=1|PronType=Prs	12	nsubj	12:nsubj	_
12	lack	lack	VERB	VBP	Mood=Ind|Number=Plur|Person=1|Tense=Pres|VerbForm=Fin	0	root	0:root	_
13	sufficient	sufficient	ADJ	JJ	Degree=Pos	14	amod	14:amod	_
14	information	information	NOUN	NN	Number=Sing	12	obj	12:obj	_
15	to	to	PART	TO	_	18	mark	18:mark	_
16	second	second	ADV	RB	NumType=Ord	18	advmod	18:advmod	SpaceAfter=No
17	-	-	PUNCT	HYPH	_	18	punct	18:punct	SpaceAfter=No
18	guess	guess	VERB	VB	VerbForm=Inf	14	acl	14:acl:to	_
19	(	(	PUNCT	-LRB-	_	18	punct	18:punct	SpaceAfter=No
20	or	or	CCONJ	CC	_	22	cc	22:cc	_
21	even	even	ADV	RB	_	22	advmod	22:advmod	_
22	know	know	VERB	VB	VerbForm=Inf	18	conj	14:acl:to|18:conj:or	SpaceAfter=No
23	)	)	PUNCT	-RRB-	_	18	punct	18:punct	_
24	what	what	PRON	WP	PronType=Int	28	obj	28:obj	_
25	the	the	DET	DT	Definite=Def|PronType=Art	26	det	26:det	_
26	FBI	FBI	PROPN	NNP	Number=Sing	28	nsubj	28:nsubj	_
27	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	28	aux	28:aux	_
28	doing	do	VERB	VBG	Tense=Pres|VerbForm=Part	18	ccomp	18:ccomp|22:ccomp	SpaceAfter=No
29	.	.	PUNCT	.	_	12	punct	12:punct	_
