HARRISBURG — An appeals court ruled Monday that Pennsylvania's wiretapping law applies to text messages, throwing out evidence police had obtained by sending fake messages over a suspect's phone.

The three-judge Superior Court panel ruled that police needed a warrant under the Pennsylvania Wiretapping and Electronic Surveillance Act when reading phone messages from a suspect who did not realize his replies were being read by investigators.

The case began in March 2007, when a state trooper stopped a speeding pickup truck with Arizona plates on Interstate 80 in Clearfield County. Daryl Taylor, the driver, and Michael Amodeo, the passenger, were both arrested after police said they found 35 pounds of marijuana, methamphetamines, a .45-caliber handgun and a prepaid cell phone, according to the court opinion.

Investigators then used the phone to locate and arrest two other men — Stephen J. Lanier, 42, of Tucson, Ariz.; and Jeffrey S. Cruttenden, 48, of Breesport, N.Y.

Lanier and Cruttenden, who were arrested on drug and conspiracy charges, filed a successful legal challenge in Luzerne County court to how evidence against them was obtained. Prosecutors appealed to Superior Court, which resulted in Monday's decision.