Vehicular crash data is helpful when trying to figure out how an accident happened, and who may be at fault. However, it may be hurtful to defendants in that it may reveal liability that may not be uncovered by other means. Vehicle crash data may include anything from testing brakes to insurance reports.
In Massachusetts, a warrant is not required to collect vehicular crash data. In Commonwealth v. Mamacos, the Supreme Judicial Court of Massachusetts determined that the defendant did not have a reasonable expectation of privacy when the police tested his truck’s breaks. The first question the Court asked is did the defendant have a subjective expectation of privacy in his truck’s brakes? The Court held that it was unclear if the defendant had a subjective expectation to privacy, and turned to the second question of inquiry: does society recognize the defendant’s expectation of privacy as reasonable under the circumstances?
In Massachusetts, the Registrar of Motor Vehicles has the statutory authority to “investigate the cause of any accident in which any motor vehicle is involved.” G. L. c. 90, § 29. Section 29 requires that local police departments “notify the registrar . . . of the particulars of every accident [in which any person is killed or injured] which happens within the limits of [its] city, town or jurisdiction.” Because of the regulations set forth in Section 29, the general population would not find the defendant’s expectation of privacy reasonable. The Court held “it would stretch the Fourth Amendment’s protections too far to say that society is prepared to recognize as objectively reasonable an expectation of privacy in the braking mechanism of a motor vehicle that has come into police possession following the death of a motorist on the highway.”