With a few clicks on the Internet, police say, the suspects developed a wish list of designer clothes and jewelry, then raided the homes while celebrities were away.
"They thought it was fun, kind of an adrenaline rush," Los Angeles police officer Brett Goodkin said. "They would go in and steal the celebrity's clothes and possessions, things they could never afford on their own."
Police last week arrested four young women and two men on suspicion of burglarizing 10 homes in the Hollywood Hills. In addition to Lohan and Hilton, other victims included "The Hills" star Audrina Patridge, Orlando Bloom, Megan Fox, Brian Austin Green, Ashley Tisdale and Rachel Bilson.
Police said the teens scoured celebrity blogs and Web sites, looking for valuables, and then used the Internet to find where the stars lived.
After watching a home, they would break into poorly protected properties through doors, windows and, in one case, a doggy door. The burglaries lasted from October 2008 until September.
Items stolen "run the gamut of high-end designer clothing," Goodkin said. "You could pick a designer, and they would be among what was taken."
Police displayed an evidence photograph Wednesday depicting approximately $2 million in stolen jewelry that was recovered and returned to Hilton. The thieves snatched dozens of items of flashy, gem-encrusted jewelry, then made off with it in the socialite's Louis Vuitton bag.
The suspects include 18-year-olds Rachel Lee, Courtney Ames and Alexis Neiers, and Diana Tamayo, 19.
Several of the group graduated two years ago from the "continuation campus" at Indian Hills High School in suburban Agoura Hills, said Donald Zimring, superintendent of the Las Virgenes Unified School District.
Such campuses are for students struggling to attain good grades in regular schools, but Zimring could not comment on their academic records.
Additionally, 18-year-old Nicholas Prugo was arrested last month in the same case on suspicion of breaking into the homes of Lohan and Patridge. A sixth suspect, 27-year-old Ray Lopez Jr., was also arrested.
Police also sought Jonathan Ajar, also 27, for a variety of offenses, including receiving stolen property and possession of a firearm.
Prosecutors have filed felony residential burglary charges against Neiers, Ames, Tamayo and Lopez Jr. They declined to file charges against Lee, pending further investigation, and additional charges will be filed against Prugo, who had already been charged with burglaries at Lohan and Patridge's homes.
Police recovered three guns and a large amount of drugs as they served search warrants in the case. They did not specify where they searched.
The robberies were driven by "celebrity infatuation and greed," Goodkin said.
Neiers had been the subject of a reality-TV pilot episode that the Los Angeles Times said was about aspiring actresses.
The cable network E! would not confirm that, but network officials issued a brief statement they "are concerned by recent events, awaiting further details and will be monitoring the situation closely." The statement said shooting began recently and would continue.
In a short interview on E!'s Web site, Neiers said she was eager to put the matter behind her.
"I just learned my lesson that I need to make some better friends and some better decisions as far as my friends go," she said.
An attorney representing some of the victims said the crimes highlight the growing risks faced by celebrities in a world of unending media attention. Blair Berk worried this was putting a "bull's-eye on the forehead of celebrities."
"You cannot on a weekly basis publish pictures of the back entrance to someone's house and do stories on their collection of cars and jewelry without increasing that person's vulnerability to theft and harm," Berk said. "It's a celebrity envy thing.
"It's the new sociopath generation of 'I really like those Chanel boots.' Instead of going out and buying them, they just steal them."
Lee appeared to be the "driving force" behind the burglaries, Goodkin said. Attempts to reach her, Lopez and Ames were unsuccessful. A man who answered the phone at a number registered to Tamayo declined to comment or to say whether she had an attorney.
Court records show Lee and Tamayo were convicted of petty theft earlier this year.
Neiers' attorney, Jeffrey K. Rubenstein, released a short statement saying his client "was at the wrong place at the wrong time" and is "not the party responsible for the events that led to her arrest."
Prugo's attorney, Sean Erenstoft, downplayed his client's role in the burglaries. He declined to elaborate, but said Prugo was pleased that others had been caught.
Erenstoft said he had not yet reviewed any evidence in the case, which includes video surveillance from some celebrity homes.
Publicists for Lohan and Bloom did not immediately respond to e-mails seeking comment. Patridge's publicist declined to comment.
Paris Hilton retrieved stolen belongings, including most of her missing jewelry, from police, but did not get everything she lost, her publicist said.