どうしてそんな危険を犯すのですか。

why?; for what reason; how; in what way; for what purpose; what for

such (about the actions of the listener, or about ideas expressed or understood by the listener); like that; that sort of

danger; peril; hazard; risk

indicates direct object of action; indicates subject of causative expression; indicates an area traversed; indicates time (period) over which action takes place; indicates point of departure or separation of action; indicates object of desire, like, hate, etc.

to commit (e.g. crime); to perpetrate; to make (e.g. mistake); to break (e.g. rule); to violate; to transgress; to contravene; to rape; to violate; to ravish; to deflower

indicates possessive; nominalizes verbs and adjectives; substitutes for "ga" in subordinate phrases; (at sentence-end, falling tone) indicates a confident conclusion; (at sentence-end) indicates emotional emphasis; (at sentence-end, rising tone) indicates question

be; is

indicates a question (sometimes rhetorical); or; whether or not; some- (e.g. something, someone); indicates doubt, uncertainty, etc.; emphatic prefix; suffix forming adjectives or adverbs; in that way