STARKE, FLA., JAN. 23 -- Serial killer Theodore Robert Bundy today expressed remorse for the murders he committed and traced his urge to kill to a compulsive fascination with hard-core pornography, according to an antipornography activist who interviewed him just hours before he was to die. Bundy met with James C. Dobson of Pomona, Calif., who has campaigned against pornography through his organization called "Focus on Family." "The main message of that hour was a message to the American people about pornography," Dobson said. He said Bundy told him that his execution -- set for 7 a.m. Tuesday -- will protect society from further danger from Bundy. "But at the same time, he said that there are many, many other people out there addicted to pornography," Dobson said. Dobson said Bundy invited him to the prison to videotape a final interview. He said the killer wept "several times" during the taping and broke down when Dobson asked whether he had anything to say to the families of the victims. The execution of Bundy, 42, in the electric chair at Florida State Prison was to be witnessed by a dozen reporters and a dozen law enforcement officers, including the Pensacola police sergeant who arrested him in early 1978. After that arrest, Pensacola police asked Bundy the number of murder cases in which he might be involved. They said he told them that it could be on a scale of "three digits." In the past three days, he has confessed to many murders in western states. The scope of Bundy's killing spree extended far beyond the comprehension of police who pursued him, according to a Seattle police detective who interviewed Bundy last Friday. "He's definitely done a lot," said Robert Keppel, a detective who began tracking Bundy in 1974 after nine young women disappeared in Washington state. "He's definitely a premier serial killer. He's probably the model." Bundy canceled a news conference that had been scheduled today and spent much of the day with his attorneys and a psychiatrist, Dorothy Lewis, prompting speculation about a final ploy to spare his life. If a credible person were to declare to Gov. Bob Martinez (R) that Bundy were insane, under state law he could not be executed. He could be hospitalized until declared sane, then executed. Martinez said in Tallahassee that three psychiatrists were prepared to examine Bundy if anyone questioned his competency. But Dobson said he thinks Bundy is sane. He said Bundy described a thirst for more and more violent pornography that began in adolescence and increased until "there was nothing more that would give him that high." Then, Dobson said, Bundy "thought about it for a year or so before he did his first killing." Afterward, he suffered guilt and anguish for six months, but said that eventually the feelings went away. "He killed a second time, only this time the agony was easier to cope with," Dobson said. "He got to the point where he didn't have that remorse." Bundy's attorneys made last-minute court appeals on his behalf, but the Supreme Court tonight rejected three separate emergency requests that would have stayed the electrocution pending another formal appeal. The justices had already rejected formal appeals four times, most recently last week on a 7-to-2 vote. Bundy was to be executed for the kidnap-murder of 12-year-old Kimberly Dianne Leach in Lake City, Fla., in 1978. He also has been sentenced to death for killing two Florida State University sorority sisters. In a taped interview with Seattle media made available by NBC affiliate KING-TV, Keppel said Bundy's attorneys invited him to the prison and asked that he also contact officials in Oregon, Idaho, Colorado, Utah and California. Keppel said police suspect that Bundy was involved in several unsolved cases in northern California and the Palo Alto area where he attended Stanford University for one quarter in the early 1970s. Keppel has spent more time with Bundy than any law enforcement officer, in part because Bundy liked talking to him and frequently wrote to him, Keppel said. Keppel said there was not enough time to talk about every case with Bundy. "We're probably only going to know at the most the 23 or 24 that are most publicized," he said. "Ted is totally consumed with murder 24 hours a day," Keppel said. "He was constantly searching for victims, planning his next murder, visiting the dump sites." Keppel returned to Seattle after disclosing frustration with a case that has spanned most of his career. "I'm going to feel we didn't get enough out of him," he said. Staff writer Myra MacPherson contributed to this report.