LOS ANGELES – Lindsay Lohan's best bet for avoiding jail time is to go back into rehab yet again and remove herself from a high-flying party lifestyle -- if not, she could be facing up to six months behind bars, legal observers said Wednesday.
Lohan, 21, was less than two weeks out of a recovery program and was voluntarily wearing an alcohol-monitoring device when she was arrested Tuesday in Santa Monica for investigation of misdemeanor driving both under the influence and with a suspended license, and felony cocaine possession.
Her lawyer, Blair Berk, has said she had a "relapse" and was receiving medical care at an undisclosed location.
A call to Lohan's publicist was not returned Wednesday.
The actress completed more than six weeks in rehab less than two weeks ago, and had checked into another recovery clinic in January.
Over the weekend, she was photographed at a party in a pink bikini, with the monitoring device on her ankle.
That behavior won't cut it anymore and neither will spa-style clinics, said Barry Gerald Sands, a Century City defense attorney who's also a certified drug and alcohol counselor.
"Whatever you have done in the past, do a 360-degree turn and go the other way," Sands said Wednesday. "She has to change her alleged friends, people sharing or selling her drugs. She has to lead a clean and sober life.
"Silk-sheet recovery homes don't do the job."
If Lohan is charged with a crime, she could ask a judge to order her to remain in rehabilitation while she awaits trial, Sands said.
A "recovery team" should be in place that includes doctors and addiction specialists who can give the judge alternatives to jail. And if she is convicted, the rehab time would count against whatever jail sentence is issued, Sands said.
Lohan has never been convicted of a drug or alcohol crime and judges routinely place first-time DUI offenders on probation rather than behind bars. However, Lohan's case could be complicated because she also was arrested for investigation of felony DUI in Beverly Hills on Memorial Day after her Mercedes-Benz crashed into a curb.
That case was submitted to the Los Angeles County district attorney's office last week and is being reviewed, spokeswoman Jane Robison said.
If she is convicted of two felonies in the two cases, she might be eligible for 18 months or more in state prison but such a sentence is unlikely, said Lawrence Taylor, a former Los Angeles prosecutor who runs one of the nation's top DUI defense law firms.
"Our prisons are packed already," he said. "We don't need some recreational (drug) users with a small amount of coke with a clean record."
On the other hand, Lohan probably will have to do some time in county jail simply because prosecutors and judges saw the backlash when Paris Hilton was briefly allowed to serve her DUI sentence at home instead of jail.
"They're going to see how sensitive everything was ... Everything was being looked at with a microscope and broadcast to the entire world, literally," Taylor said. "They saw what happened and judges do run for re-election, and deputy DAs are aware that their bosses run for re-election."
Both sides would be interested in stalling a court case until the media frenzy ebbs but that is unlikely if the continued scrutiny of Paris Hilton is any signpost, Taylor said.
"Entertainment has become more important than information and the media is looking ... for money. They're looking for audience, they're looking to give the public what they want," he said.
That scrutiny means that Lohan, if convicted, probably will get some jail time regardless of whether it is warranted in her case, Taylor said.
"I would say this woman's going to be doing at least 30 days" and perhaps as long as 180 days if she is convicted of two DUIs along with drug possession, Taylor said.
However, virtually all DUI cases are settled by plea agreements.
If he were running the defense, Taylor said, his team of experts would reconstruct the traffic accident; seek out witnesses, videotapes and audio of the traffic stops; examine repair and usage records for police breath analysis machines; and look into any blood tests Lohan was given to detect drugs and check the qualifications of the officers who stopped her. Medical experts also would check to see if Lohan had some medical condition -- say, diabetes -- that can affect the tests.
"After a few months of hard work, you can find where all the cracks are -- and there will be some," Taylor said.
Then, "I would strongly suggest ... that perhaps this woman needs rehab rather than a long stretch in jail."
A prosecutor faced with possibly losing a case might agree, otherwise, Taylor said, "your much-cherished conviction rate is going to go down and your chances of promotion are going to go down."
Taylor concedes that the type of defense that celebrities can afford is off-limits to the average DUI defendant -- and that affects the severity of their sentencing.
"Are you saying does justice have a price? Absolutely. But the same is true of heart surgery," Taylor said. "It's not going to be the same cost and it's not going to be the same result."
• Learn more in FOXNews.com's Lindsay Lohan Celebrity Center.