The 19-year-old had a huge movie poster hanging in his Oakton, Va., bedroom and a trench coat like the one worn by Neo, Keanu Reeves's character. He bought a 12-gauge shotgun, similar to one of the weapons Neo uses to fight the Matrix-generated "agents" in the movie.
And on Feb. 17, Fairfax County police say, he walked into his family's basement and shot his father seven times with the shotgun and his mother twice. He then called the police - twice - to calmly report the killings.
Cooke's fascination with the movie is shared by others who also have been charged with murder. Some high-profile crimes since the movie's 1999 release have allegedly been committed without any obvious motive other than attempts to escape The Matrix.
The premise is that in the late 20th century, once man perfected artificial intelligence in computers, the computers took over the Earth, which was mostly destroyed in the process.
Hundreds of years later, the computers have "harvested" the bodies of humans to provide energy, while the minds of those harvested humans exist in a computer-generated virtual world that mimics the late 20th century: The Matrix.
It is not uncommon for slaying suspects, especially those who are mentally unstable, to raise whatever is hot in popular culture in their defense or in interviews with police. And experts agree that one film alone is unlikely to spark that kind of violence.
But to the vulnerable psyches of those who may be mentally ill, films with suggestions of hidden evil and uncertain reality can reinforce paranoia and fear by helping unhealthy fantasy worlds to flourish, the experts say.
The cases in which "The Matrix" has emerged as a central theme span the country. Even last fall's sniper shootings in the Washington, D.C., region have overtones from the popular film. "Free yourself of The Matrix," sniper suspect Lee Boyd Malvo, 18, wrote in his jail cell. "You are a slave to The Matrix "control.' "
Earlier this month, in Ohio, a woman who told police that she lived in The Matrix and that "they commit a lot of crimes in The Matrix" was found not guilty by reason of insanity to charges of killing her landlord.
And in San Francisco, a man who believes he was sucked into The Matrix also was found not guilty by reason of insanity on charges that he killed his landlord.
Warner Bros. Pictures, which released the sequel "The Matrix Reloaded" last week, said there is no connection between the movie and the killings. In a statement, the studio expressed condolences to the victims of violent crimes. "However," the statement said, "any attempt to link these crimes with a motion picture or any other art form is disturbing and irresponsible."
But many lawyers are continuing to search for any links between art and actuality to defend their clients.
"The Matrix" has developed a huge following in the years since its release, enchanting fans with dazzling effects and a story incorporating aspects of doomsday, man-vs.-machine and biblical allegory.
"He's just obsessed with it," said Rachel M. Fierro, the attorney defending Josh Cooke against charges that he murdered his parents, Paul C. Cooke, 51, and Margaret Ruffin Cooke, 56. "I don't know why he's obsessed. . . . That's one of the reasons we've requested a neutral, independent psychiatrist - to determine whether he was sane and knew the difference between right and wrong."
A psychiatrist was appointed by Fairfax Circuit Court to examine Cooke after Fierro said in a motion that Cooke "harbored a bona fide belief that he was living in the virtual reality of "The Matrix' at the time of the alleged offenses."
Even experts who have studied the effects of violence in the media do not generally think that one film or one television show can launch such a violent impulse. But they believe that the cumulative effect of media violence in movies such as "The Matrix" can lead to actual crime, particularly in younger people and those already susceptible.
"When somebody commits a violent crime, you can't point to just one cause," said Joanne Cantor, a communications professor at the University of Wisconsin who has studied the effects of television and movie violence. But, she added, "I think these things can have really devastating effects on really vulnerable people. . . . If people are saying they were influenced by that movie, that movie was probably on their mind when they were planning these things."