A series of cases have addressed the permissible extent of a gang expert's testimony. "In People v. Olguin (1994) 31 Cal.App.4th 1355, 1371, the court explained that 'the requirements for expert testimony are that it relate to a subject sufficiently beyond common experience as to assist the trier of fact and be based on matter that is reasonably relied upon by an expert in forming an opinion on the subject to which his or her testimony relates. Such evidence is admissible even though it encompasses the ultimate issue in the case. ' On the other hand, 'expert opinion is not admissible if it consists of inferences and conclusions which can be drawn as easily and intelligently by the trier of fact as by the witness.' " (People v. Valdez (1997) 58 Cal.App.4th 494 at p. 506.) The trial court has wide discretion to admit or exclude expert testimony and we may not interfere unless a clear abuse of discretion is shown. (Ibid.) For example, in People v. Harvey (1991) 233 Cal.App.3d 1206, a police officer testified as an expert about cocaine trafficking, that the defendants' various activities were drug related or consistent with the activities of drug trafficking. The officer also testified that one defendant "was a 'distributor/trafficker,'" and that two others "were cocaine dealers." (Id. at p. 1217.) The court held the testimony was properly admitted because "the subject matter was sufficiently beyond the common expertise of the trier of fact to render expert testimony not only helpful but necessary for an understanding of the meaning and import of various actions." (Id. at p. 1228.) In People v. Gardeley (1996) 14 Cal.4th 605, an expert was given the facts of the case and asked, hypothetically, whether the described incident would be "'gang-related activity.'" (Id. at p. 619.) The expert opined "that it was a 'classic' example of gang-related activity, explaining that criminal street gangs rely on such violent assaults to frighten the residents of an area where the gang members sell drugs, thereby securing the gang's drug-dealing stronghold." (Ibid.) In People v. Gamez (1991) 235 Cal.App.3d 957 (overruled on other grounds in Gardeley, supra, 14 Cal.4th at p. 624, fn.10), the defendant was convicted of assault with a firearm when he shot at several individuals in front of a house where a rival gang member's car was parked; that individual was thought to have been involved in another gang shooting. The evidence established that the defendant drove to a location in rival gang territory. The gang expert testified that Hispanic gangs in that area were extremely territorial and venturing in another gang's "'turf'" is "done at great risk." (Gamez, supra, 235 Cal.App.3d at p. 978.) The expert further testified that, in the culture of gangs, the shooting by a rival gang member "could not go unavenged and would warrant a retaliatory strike." (Ibid.) In People v. Zermeno (1999) 21 Cal.4th 927, the gang expert testified that in his opinion, an assault committed between members of rival gangs was "'classic' behavior in gang incidents," and represented one gang member "'protecting the back of the person who is doing the assault.'" (Id. at pp. 929-930.) In People v. Zepeda (2001) 87 Cal.App.4th 1183, the court held a gang expert was properly permitted to respond to a hypothetical question, based on the facts of the case, and that in his opinion, certain behavior by a known gang member was likely done for gang-related purposes. (Id. at pp. 1208-1209.) In People v. Muniz (1993) 16 Cal.App.4th 1083, an officer testified that in his opinion the defendant, a known gang member, was preparing to commit a drive-by shooting when he was observed holding a loaded semiautomatic rifle in an illegally parked car with three other known gang members. (Id. at pp. 1085-1086.) Muniz held the expert testimony was appropriate because the officer based his opinion on facts he observed, not on inferences based on an incident to which the defendant was not connected. Moreover, the defendant's conviction was based on not only these observations, but also the defendant's admission. (Id. at p. 1088.) In Valdez, the issue was whether the trial court had abused its discretion in allowing the prosecution's gang expert to testify that the defendant had acted for the benefit of a gang, where the defendant argued the issue was one of fact for the jury. (Valdez, supra, 58 Cal.App.4th at p. 507.) The pertinent facts were that a group of individuals from a number of different Norteno cliques or gangs in San Jose came together one day and formed a caravan to attack Surenos. Valdez explained that if the evidence had been that most or all of the participants in the caravan were from the same Norteno gang, then the jury might have been able to determine whether the crime was committed for the benefit of the gang as easily as an expert. (Id. at p. 508.) Valdez concluded the facts of the case were not so simple. "The participants in the caravan were a diverse group, with affiliations to different gangs. They united for one day to attack Sureos. At the time it assembled, the caravan was not a 'criminal street gang' within the meaning of the enhancement allegation. Moreover, their common identification as Norteos did not establish them as a street gang, for, as the gang expert testified, Norteo and Sureo are not the names of gangs." (Ibid.) Valdez concluded the particular facts of the case were such that the jury could not determine whether a crime had occurred without the assistance of an expert. (Id. at pp. 508-509.) In contrast to these cases, People v. Torres (1995) 33 Cal.App.4th 37 reached the opposite result as to the permissible extent of an expert's opinion testimony. The defendant was convicted of first degree murder with a robbery special circumstance. The defendant collected money from drug dealers in return for the privilege of selling drugs in a particular area. (Torres, supra, 33 Cal.App.4th at p. 42.) A police officer testified to the legal meaning of the terms "robbery" and "extortion," and to his opinion that the crimes committed were robberies. Torres held the expert's testimony was improper because, under the facts of the case, "expressing the opinion the crimes were robberies was tantamount to expressing the opinion defendant was guilty of robbery and the first degree felony murder of the victim." (Id. at p. 48.) Torres explained: "A consistent line of authority in California as well as other jurisdictions holds a witness cannot express an opinion concerning the guilt or innocence of the defendant. ... The reason for employing this rule is not because guilt is the 'ultimate issue of fact' to be decided by the jury. Opinion testimony often goes to the ultimate issue in the case. Rather, opinions on guilt or innocence are inadmissible because they are of no assistance to the trier of fact. To put it another way, the trier of fact is as competent as the witness to weigh the evidence and draw a conclusion on the issue of guilt." (Torres, supra, 33 Cal.App.4th at pp. 46-47.) Torres held the same rationale prohibited the expert from expressing an opinion as to whether a crime had been committed. "... The rationale for admitting opinion testimony is that it will assist the jury in reaching a conclusion called for by the case. 'Where the jury is just as competent as the expert to consider and weigh the evidence and draw the necessary conclusions, then the need for expert testimony evaporates.' There are some crimes a jury could not determine had occurred without the assistance of expert opinion as to an element of the crime. Robbery and extortion, however, are not among them. Neither, unfortunately, is 'sufficiently beyond common experience' that the jury needs an expert to determine whether they have been committed. The jury clearly was competent to determine from the evidence and the court's instructions whether defendant intended to rob or extort the victims." (Torres, supra, 33 Cal.App.4th at p. 47.) Torres further found that while defense counsel's failure to object to the expert's opinion constituted ineffective assistance, the error was not prejudicial because it was not reasonably probable the result of the proceeding would have been different, but for counsel's error. (Torres, supra, 33 Cal.App.4th at p. 49.) Torres held the evidence "supported a finding on all the elements of robbery," and "we do not believe the jury could reasonably have reached any other conclusion than defendant's acts constituted attempted robbery of the victims." (Id. at p. 52, fn. omitted.) People v. Killebrew (2002) 103 Cal.App.4th 644 similarly held a gang expert's opinion testimony went too far in the context of that case. In that case, two people died during a drive-by shooting at a Country Boy Crips gathering at Casa Loma Park. The police suspected the fatal shooting was performed by members of the rival East Side Crips and anticipated there would be retaliation. The police were on a heightened state of alert and observed three cars driving in East Side Crip territory, and recognized a member of that gang in one of the cars. The officers eventually detained all three cars, and believed the group of East Side Crips was traveling together because they anticipated retaliation from the Country Boy Crips. A gun was found inside one car, and a second gun was found near the location where the cars were stopped. (Killebrew, supra, 103 Cal.App.4th at pp. 647-648.) There was no direct evidence the defendant was in any of the cars. The police positively identified every occupant of two of the cars, but saw two unidentified men walk away from the third car. The defendant was seen in the area of the traffic stops, and was arrested and charged with conspiracy to possess a handgun, based on one of the guns found with the three cars. (Id. at pp. 648-649.) Killebrew held the trial court improperly permitted the testimony of a police officer who appeared as the prosecution's gang expert. Killebrew acknowledged the officer properly testified about the dispute between the two gangs, that the fatal shooting was a major gang event, the East Side Crips would expect retaliation from the Country Boy Crips, and the defendant and the occupants of the cars were members of the East Side Crips. (Killebrew, supra, 103 Cal.App.4th at pp. 650-652.) The officer's testimony, however, "went much further." (Id. at p. 652.) "The officer also testified that when one gang member in a car possesses a gun, every other gang member in the car knows of the gun and will constructively possess the gun," (ibid.) and offered the following reasons: "... First, all the occupants in the cars were East Side Crips. Second, since the Casa Loma Park shooting was such an important event to gang members, the East Side Crips would only travel in large groups for their mutual protection that night. Third, any group of East Side Crips that ventured out that night would be armed for protection since retaliation would be expected. Finally, he opined that everyone in the group that night would know there was a gun in the car and would mutually possess the gu`n. The officer opined that even the occupants of the Chrysler, to which no gun was ever linked, would know of the guns in the other two vehicles and would mutually possess those guns." (Killebrew, supra, 103 Cal.App.4th at p. 652, fn. 7.) The officer also testified to his opinion that the defendant was the East Side Crip's "'shot caller'" who ordered the drive-by shooting at Casa Loma Park, an opinion the court criticized as "rank speculation." (Id. at p. 651, fn. 6.) Killebrew reviewed the cases discussed ante, which permitted expert testimony as to the culture and habits of criminal street gangs, but found the officer's opinion was not admissible under any of these holdings. (Killebrew, supra, 103 Cal.App.4th at pp. 657-658.) "None of these cases permitted testimony that a specific individual had specific knowledge or possessed a specific intent." (Id. at p. 658.) "... Through the use of hypothetical questions, the officer testified that each of the individuals in the three cars (1) knew there was a gun in the Chevrolet and a gun in the Mazda, and (2) jointly possessed the gun with every other person in all three cars for their mutual protection. In other words, the officer testified to the subjective knowledge and intent of each occupant in each vehicle. Such testimony is much different from the expectations of gang members in general when confronted with a specific action."The officer's testimony was the only evidence offered by the People to establish the elements of the crime. As such, it is the type of opinion that did nothing more than inform the jury how the officer believed the case should be decided. It was an improper opinion on the ultimate issue and should have been excluded. "Moreover, this topic is not one for which expert testimony is necessary. Testimony that a gang would expect retaliation as a result of a shooting such as occurred at Casa Loma Park, that gangs would travel in large groups if expecting trouble, that in a confrontation more than one gang member may share a gun in some identified circumstances, and that oftentimes gang members traveling together may know if one of their group is armed, would have been admissible. Beyond that, the officer simply informed the jury of his belief of the suspects' knowledge and intent on the night in question, issues properly reserved to the trier of fact. The officer's beliefs were irrelevant." (Killebrew, supra, 103 Cal.App.4th at p. 658.) Killebrew also found there was no evidence to place the defendant in any of the vehicles, his mere presence near the area of the traffic stops was insufficient to connect him to any of the weapons found in the cars, and reversed the defendant's conviction and barred any retrial. ( Killebrew, supra, 103 Cal.App.4th at pp. 660-661.) "Killebrew does not preclude the prosecution from eliciting expert testimony to provide the jury with information from which the jury may infer the motive for a crime or the perpetrator's intent; Killebrew prohibits an expert from testifying to his or her opinion of the knowledge or intent of a defendant on trial. " (People v. Gonzalez, supra, 126 Cal.App.4th at p. 1551; see also People v. Gonzalez, supra, 38 Cal.4th at pp. 946-947 & fn. 3.) In re Frank S. (2006) 141 Cal.App.4th 1192 followed Killebrew and also rejected the expert's opinion testimony. The police arrested a minor who possessed a concealed fixed-blade knife, a bindle of methamphetamine, and a red bandana. The minor explained that he carried the knife to protect himself from a southern gang because they thought he supported the northern street gangs. The minor also stated he had several friends in the northern gangs. The minor was charged with possessing a concealed dirk or dagger, with an enhancement for committing the crime for the benefit of a gang under section 186.22, subdivision (b)(1). To prove this allegation, the prosecution relied almost exclusively on testimony of a gang expert who, among other things, opined that the minor possessed the knife with the specific intent to benefit the gang. (Frank S., supra, 141 Cal.App.4th at pp. 1195-1196.) "When asked her opinion of the minor's purpose for the knife, the expert stated the minor possessed the knife to protect himself. She also stated a gang member would use the knife for protection from rival gang members and to assault rival gangs. When asked how the minor's possession of the knife benefited the Nortenos, she responded it helps provide them protection should they be assaulted." (Frank S., supra, 141 Cal.App.4th at pp. 1195-1196.) In Frank S., the Court reversed the juvenile adjudication because the offense was "found to be gang-related based solely upon the minor's criminal history and gang affiliations." (Frank S., supra, 141 Cal.App.4th at p. 1195.) The gang expert improperly testified as to her belief "of the minor's intent with possession of the knife, an issue reserved to the trier of fact." (Id. at p. 1199.) "The prosecution did not present any evidence that the minor was in gang territory, had gang members with him, or had any reason to expect to use the knife he was charged with concealing in a gang-related offense." (Ibid.) Under those circumstances, the court determined there was insufficient evidence to support the gang enhancement. (Ibid.)