In what circumstances will a court grant a wiretap warrant for a paid informant?

Similarly, in United States v. Bennett, supra, 219 F.3d 1117, the authorities were attempting to gather evidence of a drug conspiracy. They had successfully used a paid informant to make several buys. In a declaration, the agent seeking the wiretap acknowledged that other investigative techniques were available, but were not likely to produce useful information. The agent asserted that "[s]uspect interviews, grand jury subpoenas, and search warrants would also alert the suspects to the ongoing investigation." (Id. at p. 1122.) In upholding the issuance of the wiretap, the court noted that in order to meet the necessity requirement, the police need not pursue investigative techniques "to a point where the investigation becomes redundant or impractical or the subjects may be alerted and the entire investigation aborted by unreasonable insistence upon forlorn hope." (Ibid.) The court further explained that "the mere attainment of some degree of success during law enforcement's use of traditional investigative methods does not alone serve to extinguish the need for a wiretap. [Citation.]" (Ibid.)