Even a Strong Case by D.A. Can Be Tested by Defense : Strategy: Simpson lawyers will try to keep out evidence from search, 911 tapes. It will not be easy, experts say.

It can appear to be a powerful case: blood tests seem to link the suspect to the scene, a search conducted under a warrant uncovers incriminating items and police have evidence showing that the suspect had brutalized the victim before.

But skillful defense work--and the right set of circumstances--can unravel the most carefully crafted prosecutions.

Lawyers for O.J. Simpson are expected to file a variety of motions to try to keep out evidence that allegedly ties the famed former athlete to the murders of his ex-wife and her friend. On Tuesday they are scheduled to argue a motion to suppress evidence from a search of Simpson’s home June 13. They also may eventually try to exclude other evidence, including his statements to police, old 911 tapes of Nicole Brown Simpson calling for help as a man identified as O.J. Simpson raged in the background, and the results of DNA tests that might indicate that blood and hair found at the murder scene match Simpson’s.

None of it will be easy. But if Simpson’s lawyers successfully show the initial search of his home was illegal, the prosecution could lose key evidence: the bloody glove that apparently matches one found at the murder scene and possibly even blood found on Simpson’s driveway.

“It would be an amazing event that the most crucial piece of evidence in a high-profile murder case was thrown out,” said Cristina Arguedas, a Bay Area criminal defense attorney. “That would take one gutsy judge.”

But such motions have succeeded before in long-shot cases. In a Bay Area case, a man facing 40 years in prison after drugs and a machine gun were found in his home was set free because police had made a false implication in applying for the search warrant.

In the Christian Brando murder case in 1991, the same lawyers who are defending Simpson successfully kept out Brando’s statements to police because an officer had omitted a phrase in the reading of the Miranda rights.

And a Court of Appeal in San Francisco ruled DNA evidence inadmissible two years ago because of scientific uncertainty over how to calculate the odds of a match.

Admissibility of the Search

In the pending motion to suppress evidence, Simpson’s lawyers argue that the police, scaling a five-foot-high fence, illegally entered the grounds of the ex-athlete’s Brentwood home when they first went there at 4:30 a.m. on June 13 to notify him of his ex-wife’s death.

Once on the grounds, police found the bloodstained glove. Later, they noticed blood leading from Simpson’s white Ford Bronco on the street to his front door, according to an affidavit by Los Angeles Police Detective Philip L. Vannatter.

Police are required to obtain a warrant to search someone’s property except under certain conditions, such as when they are pursuing a fleeing suspect or attempting to preserve evidence they fear is about to be destroyed.

Even a search done with a warrant can be unlawful if police misrepresented an important fact in seeking it. Simpson’s lawyers contend that police inaccurately characterized Simpson’s absence in their warrant application by stating that he had left on an “unexpected” flight to Chicago, even though they knew he was on a planned business trip.

But defense lawyers said a warrant can only be thrown out for deliberate misrepresentation if the magistrate would not have issued it without the false statements.

Some defense attorneys said Thursday they believe the warrant might be upheld when it is heard next week because police said they saw “what appeared to be human blood” on the driver’s door handle of Simpson’s Bronco, which was parked on the street. That evidence alone, they said, might have been enough to obtain the search warrant.

Others said it would not be enough.

“The mere presence of bloodstains on the white Bronco parked on a public street might not be enough to say there was exigent circumstances to go inside the estate, unless that blood was very fresh,” said UCLA criminal law professor Peter Arenella.

Several lawyers said it was difficult to make a definitive assessment because critical facts have not been revealed yet. Los Angeles criminal defense lawyer Barry Levin noted that “Vannatter’s affidavit is devoid of key details. It says nothing about jumping the fence or the purpose for which the entry was made.”

San Francisco Public Defender Jeff Brown said: “If you are going to climb over someone’s fence, you better get a warrant. You are stupid if you don’t. You are just screwing up somebody’s case.”

The Police Interview

As the case proceeds, Simpson’s lawyers also may try to prevent the prosecution from using his statements to the police prior to his arrest. Against the advice of his then-attorney, Howard Weitzman, Simpson talked to police by himself for three hours on the day after the slayings.

But if Simpson waived his Miranda rights after talking to his attorney, trying to keep out his statements is “going to be very hard in this case,” said Bay Area defense attorney Ted Cassman. Prosecutor Marcia Clark has said that Simpson gave all the proper waivers.

It is not yet known what Simpson told the police, but defense attorneys say prosecutors could try to use any inconsistencies in his statements against him.

The 911 Tapes

Legal experts said the Simpson defense probably would have better luck in excluding the 911 tapes from the trial, an issue that could arise after the preliminary hearing.

A judge would first have to decide whether the tapes were relevant to the murder charges against Simpson, and secondly, whether their relevance was outweighed by the prejudice they would create against the defendant.

Prior Evidence of Violence

Even without the tapes, Simpson’s alleged assaults against his former wife could be admitted into evidence.

“The courts have a great deal of discretion,” Brown said.

Court rulings on admitting evidence of prior abuse in such cases have been divided. In a 1983 murder case, a state appellate court held that evidence that a husband dragged his wife outside their home, sprayed her with a hose and yelled obscenities at her was irrelevant and inadmissible. The court said there was no close connection between the husband’s previous action and the wife’s death.

But in another case three years later, a different state appellate court held that a prior assault was admissible because it showed motive to kill and ill will.

Prior violence is generally admissible if it demonstrates that the defendant acted according to a common scheme or plan. For example, evidence that linked a defendant to a signature murder where a playing card was left on the victim could be used to buttress evidence against him in a nearly identical murder.

“But there is no common scheme or plan between an allegation of hitting during an argument and breaking down the door,” said an experienced San Diego criminal defense lawyer, referring to two incidents that sparked Nicole Simpson’s previous calls to the police. “That is not even close to what we are talking about in this case.”

The Controversy Over DNA Testing

DNA evidence could also be problematic. Most courts in the country admit such genetic evidence but California’s appellate courts have been divided on the question and the California Supreme Court has not yet ruled on it.

A Court of Appeal in San Francisco held two years ago that a critical part of DNA evidence--the statistics showing the chance that someone other than the defendant would have the same genetic profile--was inadmissible. The court excluded the evidence on the grounds that scientists were in fundamental disagreement about the validity of statistical methods used by the FBI and a private testing lab in the case.

In that case, the prosecution had relied on a type of DNA testing that can take two to three months and produce powerful results that juries find hard to overlook. For instance, the test can determine that the chances of another person having that DNA is only one in several million.

In a pending case, a state appellate court is being asked to rule on the validity of a DNA testing method known as polymerase chain reaction, or PCR. It can be done more quickly than the older method but does not purport to show such high odds against a similar match.

No court in California has ruled on this method. Prosecutors say it is sound but some defense attorneys are wary.

Walter Krstulja, a senior trial attorney and forensics expert in the Los Angeles public defender’s office, warns that PCR evidence can be unreliable because samples can easily be contaminated.

“The test appears very promising,” he said, “but issues of quality control and contamination still have to be worked out.”

Alameda County prosecutor Rockne Harmon, who has often used DNA results in his cases, strongly believes that the testing methods and statistical analyses are sound.

“Trial judges don’t have much difficulty ruling this evidence admissible,” Harmon said. “It is just the appellate judges who seem to be balking.”

It is believed that prosecutors in the Simpson case are relying on both methods as well as on conventional serology, a less rigorous blood testing procedure. Only serology tests will be introduced at the preliminary hearing.

Ultimately, the admissibility of any DNA test results may boil down to the credibility of the laboratory used by the prosecution and the statistical methods used to compute the odds of a match.

Some attorneys predict that the prosecution will win any fight over DNA results because previous court rulings were based on methods that are no longer used.

Who’s Who

Here is a look at some of the key people in the preliminiary hearing for O.J. Simpson:

Judge Kathleen Kennedy-Powell: Los Angeles Municipal Court Judge

Background: Appointed by former Gov. George Deukmejian in 1988. Previously a Los Angeles deputy district attorney, specializing in sexual assault cases.

O.J. Simpson: Defendant

Marcia Clark: Lead prosecutor

Background: Has worked in district attorney’s office since 1978. Major trials include the conviction of Robert John Bardo, who killed actress Rebecca Shaeffer.

William Hodgman: Deputy district attorney

Background: Director of the Bureau of Central Operations, which includes the Special Trials Division. He has prosecuted more than 80 jury trials.

Robert L. Shapiro: Lead defense attorney

Background: Clients have included Darryl Strawberry, Tina Sinatra, Johnny Carson, F. Lee Bailey and Christian Brando. Shapiro has specialized in criminal defense since 1972.

Gerald Uelmen: Defense attorney

Background: Dean of Santa Clara University Law School, he worked with Shapiro in the defense of Christian Brando.

Sara L. Caplan: Defense attorney

Background: Associate attorney in Shapiro’s office.

Source: L.A. Times news files; Office of the L.A. County District Attorney; Judicial Profiles, Los Angeles Daily Journal.

Researched by TRACY THOMAS / Los Angeles Times