From his jail cell a few days ago, 20-year-old Craig Roger Gregerson explained the reason for which he has been arrested and charged with capital murder, punishable by death, and first degree child kidnapping.

     In a case that created national media attention, he is accused of killing 5-year-old Destiny Norton, who went missing from her home in Salt Lake City July 16. Hundreds turned out to search for her. Later police found her body stuffed in a container in the basement of Gregerson's house just two doors away from her home. Police charge that he lured her to his own property, suffocated her, then abused her dead body.

     In the jail cell interview with a local TV reporter, Gregerson offered an addiction to pornography as the reason for his actions. When asked why he killed the little girl he said he was "addicted to pornography at one point. It was ruining my life and affecting my relationship with my wife. I can tell you this: I have now become a strong advocate against pornography. I do apologize to the public, and everyone else who's been involved in what happened."

     Those who profit from the production and sale of pornographic and violent material in magazines and books, on videos and television, argue that there is no evidence to prove that what they create can foster violence, and child molestation and sex crimes, in those exposed to it.

     The ugly case of Craig Roger Gregerson, and what happened to 5-year-old Destiny Norton, is at least one convincing piece of evidence that it can and does.

     It should not require a doctorate in psychology to understand that what we see and hear can influence our behavior.

     But if evidence is needed, there is serious research that proves this to be the case. For instance, the Rand Corporation in Pittsburgh has just published in the current issue of Pediatrics the results of a survey indicating that teens who listen to music full of raunchy, sexual lyrics start having sex sooner than those who prefer other songs. The Associated Press quotes the lead researcher on this project, Steven Martino, as saying: Exposure to lots of sexually degrading music "gives them a specific message about sex." Boys learn they should be relentless in pursuit of women, and girls learn to view themselves as sex objects. "We think that really lowers kids' inhibitions."

     Benjamin Chavis, who heads a network coalition of hip-hop musicians and recording industry executives, responded to the survey by asserting that explicit music lyrics are a cultural expression that reflect "social and economic realities."

     This is a familiar echo of the plaint by some Hollywood movie and TV producers who argue that when they splatter their movies and TV productions with violence, profanity and lurid sexuality, they are merely reflecting society as it is. To be asked to clean up their acts is an infringement upon their artistic freedom, they say.

     Nobody suggests that everybody addicted to pornography becomes a violent person or sexual predator. But as Corydon Hammond, co-director of the Sex and Marital Therapy Clinic at the University of Utah says: "I don't think I've ever yet seen an adult sex offender who was not involved with pornography."

     Judith Reisman, author of "The Psychopharmacology of Pictorial Pornography," sees a direct causal link between pornography and sex crimes. "In many cases I don't think we have any problem saying pornography caused (the sex offensive). We have tons of data."

      Congress has attempted legislation seeking to control pornography but found it vetoed by courts claiming the legislation hobbled free speech. The courts, on the same free speech ground, have outlawed the sale of videos in which commercial companies have edited out profanity or questionable scenes.

     A new legislative attempt may require cable TV channels, where most questionable material appears, to carry a label warning of the offensiveness but without deleting it, thus circumventing the free speech issue.

     The Kaiser Foundation has undertaken extensive research on the amount of sex-oriented and violent programming on TV and its impact on young viewers.

     The watchdog group Parents Television Council has campaigned vigorously against sex, violence and profanity on television and in other media. It has lobbied against the cable industry's mandatory inclusion of questionable channels in omnibus packages offered subscribers, arguing that subscribers should have the right to pick and choose individual channels.

     Human sexuality researcher Reisman gets it right when she says: "It's not that pornography acts like a drug. It is a drug."

John Hughes is editor and chief operating officer of the Deseret Morning News. He is a former editor of the Christian Science Monitor, which syndicates this column. E-mail: hughes@desnews.com