Los Angeles (CNN) -- Justin Bieber could learn from former teen stars Chris Brown and Lindsay Lohan how not to turn 20.
Lohan and Brown are still dealing in their mid-20s with the consequences of their bad actions at that age.
Bieber's 20th birthday is March 1. HIs last weeks as a 19-year-old have been punctuated with two arrests and a third criminal investigation that could result in a felony charge.
The "Baby" singer faces charges of drunken driving, resisting arrest and driving with an expired license after a traffic stop in Miami Beach, Florida, and an assault charge for allegedly hitting his limousine driver in Toronto. The Los Angeles County district attorney is considering a vandalism charge against him, pending a sheriff's investigation into an egg attack on a neighbor's home.
A good lawyer -- and Bieber has plenty of those -- might resolve those cases without taking his freedom. Lohan, whose offenses included two drunken driving convictions, and Brown, who pleaded guilty to beating girlfriend Rihanna, got probation, community labor and court-ordered counseling.
Probation gone bad
A lesson for Bieber might be that even if those first crimes don't bring jail time, breaking probation rules can get you locked up. The best lawyer can only help a client to a point, especially if that client fails to report to a probation officer, doesn't complete community service, tests positive for illegal drugs or gets arrested again. Ask Lohan or Brown.
Their entertainment careers have been stunted since their 20th birthdays by repeated probation violations that led to stints in rehab, months of additional community labor, frequent trips to court and occasional days behind bars.
Lohan's lesson for Bieber
Lohan did well posing for Playboy between court appearances, but her once-promising film career has been derailed by producers wary about her reliability. Red carpet walks at movie premieres were replaced by dozens of walks into a courthouse. Film critics can pan your work, but a judge can throw you in jail.
Her probation was going well for the first two years, before a prosecutor questioned if she was attending court-ordered counseling sessions. She was late for a probation hearing once, then completely missed another court date. Lohan was convicted of shoplifting a necklace. She angered a series of judges, resulting in dozens of court dates, several probation revocations, jail and rehab visits.
Lohan, who has publicly acknowledged her substance abuse struggle, appears to have finally found some balance in her life since completing treatment at the Cliffside Malibu rehab facility last year. She is still on probation.
Brown's lesson for Bieber
Chris Brown got glowing probation reports the first two years after he pleaded guilty to felony assault in August 2009. But Los Angeles prosecutors began looking closer at his behavior after reports of a bar fight with Drake, a parking lot brawl with Frank Ocean and a hit-and-run arrest. Investigators found evidence that Brown had fudged on completing the community labor requirement.
Brown voluntarily entered a rehab program in late October, days after he was arrested on an assault charge in Washington. His treatment ended abruptly when he was kicked out of the rehab program for throwing a rock through his mother's car window in the middle of a family counseling session, according to a probation report.
The judge soon revoked Brown's probation, but sent him back to rehab for 90 days instead of jail. Brown is now in a "dual diagnosis" rehab program for help with anger management and substance abuse. The latest probation report said he "is doing well in the program and making great strides" in rehab, although the prosecutor asked the judge to send him to jail because his violent outbursts were "increasing in severity and intensity." The Washington assault charge is still pending.
Brown has managed to put out new music and tour while on probation, but his legal troubles have dampened his success. When he wanted to tour Europe, he couldn't. British border officials cited concerns that Brown might pose a danger to British citizens when they barred him from entering the United Kingdom for concerts in 2010. "We reserve the right to refuse entry to the UK to anyone guilty of a serious criminal offense," said Barbara Woodward, director of the UK Border Agency's international group. "Public safety is one of our primary concerns."
A criminal record could threaten Bieber's career even more, because he is a Canadian citizen living and working in the United States on a visa. While convictions might not result in his deportation, they could make crossing the border a problem. Bieber, who has built a fortune by touring the world, has already gotten a taste of what could be.
U.S. Customs agents delayed his entry into the United States for several hours after his chartered jet landed in New Jersey's Teterboro Airport from Toronto last week. Agents interviewed him for several hours before clearing him for entry. Drug-sniffing dogs were used to search his plane, but no sign of drugs was detected and no illegal substances were found, according to a law enforcement source.
A government statement to CNN noted that there are "more than 60 grounds of inadmissibility divided into several major categories, including health-related grounds, criminality, security reasons, public charge, labor certification, illegal entrants and immigration violations, documentation requirements, and miscellaneous grounds" that could keep someone out of the country.
CNN legal analyst Paul Callan said the evidence that Bieber had Xanax in his blood when he was arrested in Florida could be viewed as "drug abuse" by U.S. border officials, if he did not have a prescription for the controlled substance.
The threats to Justin Bieber's freedom and career are still only allegations. He has not been convicted of anything. If he is eventually found guilty and placed on probation, he has the advantage of knowing from his friends Chris and Lindsay how important it is to play by the rules.