A parolee accused of killing 17-year-old Lily Burk last month could have been serving a lengthy prison sentence instead of roaming the streets of Los Angeles but for a clerical error that misstated his criminal record, according to interviews and court documents reviewed by The Times.

Because of the error, authorities did not know that Charles Samuel was eligible to be prosecuted under the state's tough three-strikes law when he was arrested for and convicted of burglary in San Bernardino County in 1997.

A San Bernardino County district attorney's official said he believed prosecutors would have filed the burglary charge as a third strike had Samuel's "rap sheet" properly shown that he had previous convictions that counted as two strikes rather than one.

"We were very aggressive on all three-strikes cases back then," said Assistant Dist. Atty. Dennis Christy.

Under the three-strikes law, offenders convicted of a third strike face a minimum prison sentence of 25 years to life.

A second opportunity to prosecute Samuel under the three-strikes law came in 2006, when he was charged with petty theft in Los Angeles. A district attorney's spokeswoman said prosecutors also reviewed Samuel's criminal records and believe that at the time his case would not have been charged as a third strike.

Even if prosecutors in L.A. County had known that he had two previous strikes, it was unclear whether they would have sought a life prison term for Samuel. Under Dist. Atty. Steve Cooley, prosecutors generally don't seek life sentences for repeat offenders unless the "third strike" involves a violent or serious crime, such as robbery.

Samuel's repeated brushes with the criminal justice system underscore the complexity of the three-strikes law and raise the possibility that Burk's slaying could have been averted.

Burk never returned to her Los Feliz home July 24 after running an errand for her mother at Southwestern Law School in the Mid-Wilshire area. That afternoon, she made two odd calls to her parents, asking how to use a credit card to withdraw cash at an ATM. Her body was discovered the next morning in her Volvo in a downtown parking lot. Her head had been beaten and her neck slashed.

Police said footage from surveillance cameras shows Samuel, 50, driving from the area of the law school in Burk's car with the high school senior in the passenger seat, with Burk at a downtown ATM and then abandoning the car in the parking lot where Burk's body was found.

Samuel's criminal record stretches over three decades and includes mostly minor theft and drug offenses.

Under the 1994 three-strikes law, prosecutors are allowed to charge any felony -- however minor -- as a third strike if a defendant has previously been convicted of two crimes considered violent or serious.

Court records reviewed by The Times show that Samuel pleaded guilty to robbery and residential burglary in 1987 in connection with a home-invasion robbery in San Bernardino.

Residential burglary and robbery qualify as violent or serious strikes under the law.

A law enforcement source who spoke on condition of anonymity said Samuel's rap sheet lists his robbery conviction but does not describe his burglary conviction as a residential burglary. Under the three-strikes law, non-residential burglaries do not count as strikes.

It is unclear who was responsible for the error.

Gary Cooper, director of the state Department of Justice division that maintains rap sheet records, said mistakes were rare but that the accuracy of the database depends largely on the information received from police, prosecutors and the courts.

"We can only put in what we get," Cooper said. He declined to talk about Samuel's case, citing state law that requires that rap sheet records remain confidential.

In the 1997 burglary case, San Bernardino County prosecutors alleged in court papers that Samuel had only one prior strike: his 1987 robbery conviction.

Christy said district attorney's records also show that Samuel was convicted in 1987 of residential burglary. But he said that prosecutors usually review a more comprehensive criminal record maintained by the state Department of Justice rather than their own files when investigating a defendant's criminal history.

"As best as I can tell, we looked at the rap sheet. From that, what we concluded is that [Samuel] only had one strike," Christy said. He declined to elaborate on the records reviewed, citing state confidentiality laws.

Samuel was convicted of burglary and sentenced to two years and eight months in prison in the 1997 case.

Had prosecutors charged Samuel with a third strike, there is no guarantee that he would have been sent to prison for life.

Judges have the authority to give shorter sentences under some circumstances.

In the 1997 case, a judge might have been willing to grant Samuel leniency given the relatively minor nature of the offense: trying to steal a bottle of alcohol from a Food 4 Less store in Barstow.

Samuel might also have benefited from a controversy surrounding whether prosecutors could consider multiple convictions from the same crime as separate strikes.

Though Christy said San Bernardino County's prosecutors were among those vigorously pursuing such cases in 1997, the California Supreme Court did not rule that such a strategy was legal until a year later.

Today, prosecutors in several counties, including Los Angeles, are more cautious about charging three-strikes cases when a defendant is accused of a relatively minor crime, such as shoplifting or drug possession.

Christy said San Bernardino prosecutors take into account public concern about using the law to severely punish minor offenses.

"I don't know today . . . that we would file this same case as a third strike," he said.

"Back in 1997, we would have."