ROSEMARY M. COLLYER, District Judge.
On the eve of trial, Defendant Noe Machado-Erazo has moved to exclude the testimony of a government expert witness, Special Agent David Magnuson of the Federal Bureau of Investigation, who would testify about cellular telephone site analysis. Mr. Machado-Erazo argues that S.A. Magnuson's testimony is not based on a sufficiently reliable methodology to be admissible
Noe Machado-Erazo is charged with offenses related to his alleged involvement in MS-13, a gang formed years ago in Los Angeles, with roots in El Salvador.
The government plans to offer the testimony of S.A. David Magnuson of the FBI Cellular Analysis Survey Team to show "that the cell phones used by defendants Machado Erazo, Jose Martinez Amaya, and a cooperating witness were in the remote area where the body of Felipe Enriquez was found on or about March 28, 2010." Gov't Opp. [Dkt. 368] at 2. S.A. Magnuson's report is 38 pages of slides, duplicated as Exhibit A to Mr. Machado-Erazo's Motion. See Magnuson Report, Def. Mot. [Dkt. 367], Ex. A [Dkt. 367-2]. The government also provided the report in its Trial Exhibit Binder, premarked as Government Exhibit 306. The report "depicts the geographic location of the cell towers/sectors utilized by the phones analyzed as they moved through the Cricket and T-Mobile cellular networks placing and receiving phone calls on the dates and times indicated." Magnuson Report at 2. The report is "based on cell records obtained by subpoena." Gov't Opp. at 2. The government emphasizes that S.A. Magnuson "will not claim to have determined the exact location of the phone user, but rather the general location where a cell phone would have to be located to use a particular cell tower and sector." Id. at 2 n. 1.
The government intends to offer S.A. Magnuson as an expert witness under Federal Rule of Evidence 702. Mr. Machado-Erazo argues that the proposed testimony is insufficiently reliable to be admissible as expert testimony. He also argues that the Court should exclude the testimony as irrelevant or, in the alternative, as unduly prejudicial under Rule 403.
Federal Rule of Evidence 701 governs opinion testimony by lay witnesses, who may testify only as to opinions that are "(a) rationally based on the witness's perception; (b) helpful to clearly understanding the witness's testimony or to determining a fact in issue; and (c) not based on scientific, technical, or other specialized knowledge within the scope of Rule 702."
A federal court serves as the gatekeeper for expert testimony. Federal Rule of Evidence 702 imposes a "special obligation upon a trial judge" to ensure that expert testimony is not only relevant, but reliable. Kumho Tire Co. Ltd. v. Carmichael, 526 U.S. 137, 147, 119 S.Ct. 1167, 143 L.Ed.2d 238 (1999). "Under Daubert [v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 592, 113 S.Ct. 2786, 125 L.Ed.2d 469 (1993)], the district court is required to address two questions, first whether the expert's testimony is based on `scientific knowledge,' and second, whether the testimony `will assist the trier of fact to understand or determine a fact in issue.'" Meister v. Med. Eng'g Corp., 267 F.3d 1123, 1126 (D.C.Cir.2001) (quoting Daubert, 509 U.S. at 592, 113 S.Ct. 2786). The first inquiry "demands a grounding in the methods and procedures of science, rather than subjective belief or unsupported speculation." Id. at 1127, 113 S.Ct. 2786; see also Daubert, 509 U.S. at 592-93, 113 S.Ct. 2786 (requiring a "preliminary assessment of whether the reasoning or methodology underlying the testimony is scientifically valid and of whether that reasoning or methodology properly can be applied to the facts in issue"). The second inquiry "goes primarily to relevance." Daubert, 509 U.S. at 591, 113 S.Ct. 2786. The presumption under the Rules is that expert testimony is admissible once a proponent makes the requisite threshold showing; further disputes go to weight, not admissibility. See id. at 588, 113 S.Ct. 2786.
There are four factors that courts generally consider in evaluating scientific validity under Daubert:
Ambrosini v. Labarraque, 101 F.3d 129, 133-34 (D.C.Cir.1996) (citing Daubert, 509 U.S. at 593-94, 113 S.Ct. 2786). "[T]he inquiry is a `flexible one,'" no one factor is dispositive, and the four-factor list is not exhaustive. Id. (quoting Daubert, 509 U.S. at 593-95, 113 S.Ct. 2786).
A trial court has "latitude. . . to decide whether or when special briefing or other proceedings are needed to investigate reliability." Kumho Tire, 526 U.S. at 152, 119 S.Ct. 1167. "District courts are not required to hold a Daubert hearing before ruling on the admissibility of scientific evidence." See In re Hanford Nuclear Reservation Litig., 292 F.3d 1124, 1138-39 (9th Cir.2002) (citing United States v. Alatorre, 222 F.3d 1098, 1100 (9th Cir. 2000)); accord Oddi v. Ford Motor Co.,
The Court denied Mr. Machado-Erazo's motion in open court on Friday, June 14, 2013, so counsel could properly prepare for trial on Tuesday, June 18, and provides its full reasoning below.
Mr. Machado-Erazo makes three arguments: (1) S.A. Magnuson's methodology is not reliable and thus fails the requirements of Federal Rule of Evidence 702 and Daubert, Def. Mot. at 5-13; (2) because it lacks reliability, the evidence is not relevant, id. at 14-15; and (3) because it lacks reliability, the evidence should be excluded under Federal Rule of Evidence 403 as unduly prejudicial, id. at 15-16. Mr. Machado-Erazo relies primarily on two bases to support his argument: a case (United States v. Evans, 892 F.Supp.2d 949 (N.D.Ill.2012)) and an article (Michael Cherry, "Prosecutors' use of mobile phone tracking is `junk science,' critics say," American Bar Journal, June 2013, attached as Exhibit B to his motion).
The core of Mr. Machado-Erazo's Daubert argument is that "[t]he evidence and methodology . . . used to substantiate the conclusion that the cell tower used to transmit a call is indicative of the defendant's location is faulty and misleading." Def. Mot. at 13. He asserts that "[Special] Agent Magnuson's report is based upon the faulty assumption that a cell phone always connects to the closest cell tower at the time a call is placed and that the cell phone coverage range can be estimated or `projected' based solely upon his own `expertise' rather than actual data." Id. at 6. In Mr. Machado-Erazo's view, S.A. Magnuson's premise is faulty because, "if the phone is not connecting to the closest tower at that time, then there is no useful correlation between the location of the tower at the time the call is placed and the location of the caller." Id. at 7. Mr. Machado-Erazo lists nine factors that, he argues, determine which cellular tower handles a given call. See id. at 8 (listing, e.g., "which tower has the available capacity," "[l]ine of sight," and "[t]he amount of interference in the area from other towers").
Mr. Machado-Erazo further argues that S.A. Magnuson's testimony "is not based upon sufficient facts or data" because "the cellular carrier does not provide data regarding the actual coverage area of any tower at the time" of any given phone call, "and there is no method for determining this in historical call detail records." Id. at 9. He asserts that S.A. Magnuson's testimony is "not the product of reliable principles
Mr. Machado-Erazo adds the argument that S.A. Magnuson's proposed testimony is not relevant under Rule 401 or is unfairly prejudicial under Rule 403. He relies on the contention that, "[i]n order to inculpate Mr. Machado-Erazo by offering the connections of various cell phones with various towers as circumstantial evidence of his and other alleged conspirators' locations, the Government must prove the preliminary fact that there is a repeatable[,] nearly 1:1 causal correlation of the cell phone signals being routed to the geographically nearest tower." Id. at 14-15; see also id. at 15 ("The direction of the antennae on a cell site with a `guess' about the range of that cell site does not tend to help make a determination of a fact that is of consequence more or less probable and certainly cannot be the basis for an inference that any particular phone was in the `vicinity' of any particular address."). Mr. Machado-Erazo argues that because "the actual methodology (or lack thereof) behind [the] plotted maps [used by S.A. Magnuson] does not support [the] conclusion" that "Mr. Machado-Erazo's phone was in certain key locations at specific times," S.A. Magnuson's testimony should be excluded under Rule 403 because it is unduly prejudicial. Id. at 16.
The government responds that the motion should be denied without a Daubert hearing. It asserts that S.A. Magnuson is qualified because he is "a highly trained Special Agent in the FBI's Cellular Analysis and Survey Team" who "has received training from the cellular service providers, worked on hundreds of cases involving thousands of hours of practical experience analyzing historical call detail records and has been qualified approximately twenty times in courts as an expert in the field of cell site analysis." Gov't Opp. at 5. The government predicts that S.A. Magnuson will testify that "the data relied upon to formulate his opinions are routinely relied upon" by both law enforcement and cell service providers. Id. Citing a representative sample of cases, the government contends that "[t]estimony about cell phone technology and the ability to determine the general area where calls are placed and received has been admitted in courts throughout the country," and the government has located no case finding "this type of evidence [to be] untrustworthy or junk science." Id. at 5-6 (citing cases). The government asserts that peer-reviewed articles are not needed to satisfy Daubert because "cell phone technology is neither novel nor particularly complex" and multiple courts have already concluded that "the underlying methodology is sound and can reliably indicate the general location of the cell phone user." Id. at 6-8 (citing cases). The government further contends that the proper methodology was reliably applied because "[c]ell site and sector analysis does not determine the exact location of a cell phone, but rather shows the general area the phone had to be located based on cell tower location and the sector of the tower used to transmit the call." Id. at 9.
Distinguishing Evans, the case heavily relied on by Mr. Machado-Erazo, the government says that Mr. Marchado-Erazo
Finally, the government suggests that no evidentiary hearing is required to assess S.A. Magnuson's proposed testimony because his methodology has been found reliable in "numerous cases across the country" and "has been tested through numerous cases investigated by law enforcement." Gov't Opp. at 9. It argues that the expert report submitted in this case establishes itself as based on sufficient data and as the product of a reliable methodology. Id. at 9.
Mr. Machado-Erazo's argument appears forceful at first blush, given his reliance on Evans, which questioned the type of expert testimony proffered here.
Mr. Machado-Erazo's motion rests on a fundamentally erroneous contention. Mr. Machado-Erazo argues that S.A. Magnuson's testimony derives from the premise "that a cell phone always connects to the closest cell tower at the time a call is placed." Def. Mot. at 6. However, the expert report submitted by S.A. Magnuson indicates that his conclusions are derived from projecting a likely area from which a call was made, based on the specific tower (and antenna) to which a call connected. See Magnuson Report at 2. In his methodology, S.A. Magnuson obtains call data from the service provider that identifies which network tower and which antenna on that tower were utilized for any given call; he does not guess or estimate which cell tower or towers were in use. Then, "using a 120-degree pie shape and extending approximately 50% to 70% of the way to the nearest cell tower," S.A. Magnuson maps "the sector of radio-frequency energy emanating from the antenna on the cell tower." Davis, 2013 WL 2156659, at *5. As a caller moves around, his call would be handed off from cell tower antenna to cell tower antenna and can be traced accordingly by the service provider. Thus, using telephone company records, S.A. Magnuson reports that he is able to determine that a given cell phone, at a particular
Jones and Davis, as well as the many cases cited therein, demonstrate that this methodology employed by S.A. Magnuson clears the hurdle imposed by Daubert and Rule 702. Notably, the Jones defendant argued "that Agent Eicher's methodology for determining the direction and size of the pie-shaped wedges [representing the direction of cell towers to which phones connected] is unreliable." 918 F.Supp.2d at 4. Judge Huvelle disagreed. She found that the government had shown that Agent Eicher's methodology was reliable and that he had relied on sufficient facts and data. Id. at *3-4. She explained Agent Eicher's methodology—which is substantially identical to S.A. Magnuson's—as follows:
Id. at *3-4 (citations omitted). Judge Huvelle also noted that "the use of cell phone location records to determine the general location of a cell phone has been widely accepted by numerous federal courts." Id. at *3 (citing United States v. Schaffer, 439 Fed.Appx. 344, 347 (5th Cir.2011); United States v. Dean, No. 09 CR 446, 2012 WL 6568229, at *5 (N.D.Ill. Dec. 14, 2012); and United States v. Fama, No. 12-CR-186 (WFK), 2012 WL 6102700, at *3 (E.D.N.Y. Dec. 10, 2012)).
The defendant in Jones advanced relevance and Rule 403 challenges similar to those advanced by Mr. Machado-Erazo here. Judge Huvelle rejected both, finding that the testimony was not barred by Rule 403 because "the government has made it clear that Agent Eicher's proposed testimony will not claim to have determined the exact location of the phone user, but rather the general location where a cell phone would have to be located to use a particular cell tower and sector." Id. at 6 (internal quotation marks and citation omitted). She also rejected Mr. Jones's argument that a Daubert hearing was required, again noting that "[t]he use of cell phone records to locate a phone has been widely accepted in both federal and state courts across the country" and that "the science is well understood and the issues [were] thoroughly briefed." Id. at 6.
In Davis, Judge Robin Rosenbaum rejected a Daubert challenge to cell site analysis testimony to be offered by the same special agent here, S.A. Magnuson. Judge Rosenbaum ruled after a hearing at which S.A. Magnuson testified. She concluded that his methodology is reliable, based in part on his extensive testimony about cell towers and networks and his methods. Davis, 2013 WL 2156659, at *4-5. Judge Rosenbaum noted that S.A. Magnuson's method, using 120-degree pie shapes extending from the tower to "50% to 70% of the way to the nearest cell tower," was tested and proven to be "very, very accurate." Id. (internal citation and quotation marks omitted); see also id. ("[W]orldwide, the FBI has used [data revealing `actual radio-frequency footprints of the sectors'] to cross-check the accuracy of sector maps drawn using the techniques employed by Agent Magnuson." (citations omitted)).
Davis reached the same conclusion, rejecting the defendant's reliance on Evans for two reasons. First, "other courts have reached the opposite conclusion of the Evans Court regarding the reliability of an agent's methodology in estimating cell sectors where the agent used cell-phone records and his general knowledge and understanding of cellular phone networks and where the agent testified that he and others had used that methodology numerous times without error." Id. at *6 (citations omitted). Second, S.A. Magnuson testified in Davis that "he was not aware of what [granulization theory] was and that he does not knowingly employ it." Id. at *6 n. 3. The Jones court used the same reasoning, also declining to rely on Evans to exclude an agent's testimony on cell site analysis. See 918 F.Supp.2d at 2 n. 2. The Jones "defendant initially argued that Agent Eicher's methodology was unreliable because he assumed that a cell phone always connects to the cell tower that is closest to it—an assumption defendant referred to as the `granulization' theory." Id. Because "the government clarified . . . that Agent Eicher does not rely on any such assumption," the defendant withdrew his argument, and Judge Huvelle dismissed his reliance on Evans as "of no help, since [Evans] focused on the granulization theory." Id. The government has offered the same clarification here, see Gov't Opp. at 2 n. 1, and the Court thus concludes that Mr. Machado-Erazo's reliance on Evans is unavailing.
On the basis of the parties' arguments, S.A. Magnuson's reports, and Davis and Jones, as well as its own experience, the Court finds that S.A. Magnuson's proposed expert "testimony is based on scientific knowledge" and is admissible under Daubert. See Meister, 267 F.3d at 1126 (internal citation and quotation marks omitted).
Because Mr. Machado-Erazo's challenges to the testimony's relevance depend
The Court concludes that no hearing is necessary to clarify the positions of the parties or the reliability of S.A. Magnuson's methodology. See Kumho Tire, 526 U.S. at 152, 119 S.Ct. 1167.
For the reasons set forth above, Defendant Machado-Erazo's Motion in Limine to Exclude the Expert Testimony and Cellular Analysis Report and Charts of S.A. David Magnuson, Dkt. 367, is denied.