Two incongruous versions of Mr. Simpson's persona will be given to the 12-member jury, and Mr. Simpson's fate will ultimately depend on which one it decides is closest to the truth.

One is the street-smart San Francisco ghetto kid who overcame tremendous odds to become a beloved star of football and Hollywood, and who is now wrongly accused of a hideous crime.

The other is a hot-tempered, hard-drinking, foul-mouthed bully who for years humiliated and terrorized the mother of his children, the woman he professed to love and cherish.

Prosecutors are expected to depict Mr. Simpson as maniacally jealous of his former wife to the point of stalking and physically abusing her in fits of rage. They will try to persuade jurors that the slayings of Nicole Brown Simpson and her friend Ronald L. Goldman were almost the logical culmination of increasingly violent and obsessive behavior.

The defense strategy, by contrast, is expected to lean heavily on the absence of a murder weapon with Mr. Simpson's fingerprints on it and, even more tellingly, on the lack of an eyewitness who can link him to the crime scene. The defense will raise questions about the victims' characters, suggesting that the killings may have been drug-related.

Prosecutors will have to explain how one man was able to overpower two younger, well-conditioned and physically agile adults without either of them apparently screaming for help. Defense lawyers will argue that it took at least two people to commit the slayings.

A crucial battleground in the case will be the relatively new science of DNA testing, which is used to determine whether blood, semen or tissue came from a victim or suspect. Prosecutors say the results of DNA tests done on samples found at the crime site and at Mr. Simpson's Brentwood estate convincingly identify him as the killer.

To challenge the case on scientific grounds,