DOVER — A judge has tossed out cellphone evidence that prosecutors were hoping to use against the former chief firearm ballistics expert for the Delaware State Police.

State police in January obtained a court order under Delaware’s wiretap statute compelling disclosure of Carl N. Rone’s cellphone records as they investigated allegations that he falsified time sheets. The information included historical call detail records, with cell site location information, or CSLI, for a two-year period from January 2016 to January 2018.

Rone was suspended from his duties in January and indicted in May on one count of felony theft and one count of falsifying business records. His trial is scheduled for Oct. 29. Authorities allege that Rone submitted time sheets for 79 days in 2016 and 2017 when he did not report for work.

To compel disclosure of the records under the wiretap statute, police had to demonstrate only that there was “reason to believe” they were relevant to a legitimate law enforcement inquiry.

Rone’s attorney argued that the compelled disclosure of cell site location information constituted a search that was made without a warrant, and without a legally recognized exception to search warrant requirements.

On Monday, Kent County Superior Court Judge Noel Primos agreed, citing a recent ruling in which the U.S. Supreme Court declared that police generally need a warrant to look at records that reveal where cellphone users have been.

The Supreme Court case involved Timothy Carpenter, who was sentenced to 116 years in prison for his role in a string of robberies in Michigan and Ohio. Cell tower records for two separate periods, one lasting seven days and one continuing for 127 days, bolstered the case against Carpenter.

As with Delaware authorities investigating Rone, police obtained the records in the Carpenter case without a warrant, relying instead on a court order that requires a lower standard than the “probable cause” needed for a warrant.

Primos rejected prosecution arguments that the application for a court order for Rone’s cellphone records met all the requirements for a search warrant. He noted specifically that Delaware’s wiretap law does not require a showing of probable cause.

“Nothing in the application states or suggests that there was a fair probability that the CSLI would contain evidence of defendant’s alleged falsification of business records,” Primos wrote.

The judge also described the conduct by Delaware authorities as even more egregious than what the Supreme Court found unacceptable in police monitoring Carpenter’s whereabouts for seven days.

“Here, defendant’s particular movements were subjected to ‘tireless and absolute surveillance’ for a period of over two years,” Primos wrote, citing language from the Supreme Court ruling.

Carl Kanefsky, a spokesman for the Delaware Department of Justice, declined to comment on the ruling.