SANTA BARBARA, Calif. -- The Santa Barbara County Sheriff's Office has concluded in a new report that the Isla Vista gunman acted alone when he went on a murderous rampage last May.
The 64-page report, which details how the killer carried out the rampage on May 23, completes the investigation of the events that left six UC Santa Barbara students dead.
Elliot Rodger, 22, fatally stabbed three men in his apartment. He then went on a drive-by shooting spree, killing three more people, and deliberately hitting people in the street with his car. Fourteen others were injured.
Rodger was involved in two gun battles with sheriff's deputies and was wounded before killing himself.
The three stabbing victims were killed separately as they entered the apartment at different times. The report says Rodger searched online for the phrase "quiet silent kill with a knife."
A search of Rodger's Internet history also found that he "was very interested in the practices and techniques of the Third Reich."
As investigators looked at what can be done to prevent a similar crime in the future, they stated, "there is no single or simple solution to the complex problems that lie beneath that question."
The report states "In California, we have some of the strongest gun control laws in the nation, yet in this case the suspect was still able to legally purchase and possess three handguns and hundreds of rounds of ammunition."
The suspect was receiving treatment for mental illness and had been since childhood, the report noted.
Rodgers had recorded a video of himself where he outlined details of the massacre.
"What is unusual in this case is the extent of the written and video-taped record of thoughts, feelings and intentions left by a suspect, who in retrospect, clearly suffered from significant mental illness that ultimately resulted in homicidal and suicidal rage," the report stated.
Stab and slash marks on a fitted sheet and several pillows suggest Rodger rehearsed his actions. In a final handwritten journal entry dated that day, he wrote: "This is it. In one hour I will have my revenge on this cruel world. I HATE YOU ALLLL! DIE."
The Associated Press contributed to this report.
Isla Vista gunman acted alone, report concludes