To most, Carolyn Warmus is a bright, energetic schoolteacher. To police, she is an obsessed woman who pumped nine shots into her lover's wife, then met the man for drinks and sex. It took a year of intense legwork by two detectives to put together the case that made a murder suspect out of the 26-year-old computer science teacher and insurance heiress. Warmus was charged with second-degree murder Monday. Police said she shot Betty Jeanne Solomon, 40, nine times on Jan. 15, 1989, then drove to a local hotel to meet her lover, fellow schoolteacher Paul Solomon, for drinks and a sexual tryst in her car. Her attorney, Charles Fiore, maintains his client is innocent. He said Thursday that she passed a polygraph test taken on the advice of her family attorney five days after the slaying. Warmus was not the initial suspect in the killing. Solomon was. ``You can compare it to a large puzzle with many, many pieces,'' said Lt. Cornelius Sullivan, head of detectives in Greenburgh, a New York City suburb near White Plains. Police would not say when their focus shifted to Warmus, daughter of a wealthy Michigan insurance executive, but a vacation trip to Puerto Rico five months after the killing may have been key in highlighting Warmus' alleged obsession with the dead woman's husband. Police said Solomon, 39, told investigators that Warmus followed him and a friend, Barbara Ballor, 28, to Puerto Rico. Once there, they said, she called a member of Ballor's family pretending to be a police officer and made disparaging comments about Solomon in an apparent effort to break the couple up. Police traced the call back to Warmus. Investigators then focused on other telephone records. The paper trail led them to Vincent Parco, a private investigator in New York City who told police he sold Warmus a silencer and a .25-caliber handgun, the same type of weapon used to kill Mrs. Solomon. Police say they linked the weapon that Parco sold to the killing through ballistics evidence, but did not elaborate. The weapon has not been recovered. On Thursday, Parco's New York City pistol permit was suspended and Parco agreed to give police his weapons, said city police spokesman Detective Joseph McConville. Law enforcement sources said Warmus knew Parco because she had hired him before to investigate an ex-boyfriend, a married bartender who lived in New Jersey. Police said Warmus, who lives in a high-rise on Manhattan's East Side, told Parco she needed the gun for protection, but Parco's ex-partner, Gabe Laura, told the New York Post she offered him three different reasons. ``We figured her for a flake,'' Laura said, adding, ``We told her to get us some proof about what she was saying and sent her away.'' Warmus and Solomon had been having an affair for a year, according to an indictment unsealed Monday. They met in 1987 at an elementary school in Greenburgh. At the time of Mrs. Solomon's murder, police said, Warmus wanted to intensify the relationship; Solomon wanted to cool things off. Investigators said he ended the affair after his wife's death. In her statement to police, Warmus said she called Solomon at home hours before the murder and they talked for 45 minutes about everything from his 15-year-old daughter Kristan's basketball team to a bar mitzvah he attended. They agreed to meet for drinks at a Yonkers hotel bar at 7:30 p.m. Mrs. Solomon was killed between 7 p.m. and 7:30 p.m., police said, adding that Warmus knew Mrs. Solomon would be home alone. Warmus told detectives they left the bar at 10:30 p.m., went out to her car in the parking lot and had sex before leaving each other about 11:30 p.m. Her attorney said Warmus frequently had dinner with the Solomon family at their home and that neighbors knew both her and her car. ``It would be a pretty good trick for her to knock on the door, kill her ... and leave and not be seen or have her car seen,'' Fiore said. Warmus' father is president of American Way Life Insurance Co. in Southfield, Mich., whose assets reportedly are about $150 million. She grew up in Birmingham, Mich.