EvidenceProf Blog

Editor: Colin Miller
Univ. of South Carolina School of Law

Wednesday, December 3, 2014

The Serial Podcast, Episode 5: The Admissibility & Discoverability of the Cell Tower Evidence

A woman is manually strangled, and her body is dumped in a park. The defendant, who had been in a relationship with the victim, becomes the suspect. There's nothing more than circumstantial evidence connecting the defendant to the murder, but two pieces of evidence are especially important: two cell phone calls whose pings tend to pinpoint the defendant's cell phone in the park when the victim's body was likely dumped there. The defendant is convicted. In 2014, more than a decade later, the defendant seeks post-conviction relief, alleging the ineffective assistance of counsel. Part of the claim is that trial counsel failed to contact a potential key witness who would have helped the defense. Part of the problem is that trial counsel has died. An alternate suspect emerges. DNA testing of crime scene evidence is done. The case I'm talking about is Roberts v. Howton, 13 F.Supp.3d 1077 (D.Or. 2014). The result? The defendant's conviction was reversed. 

I've done eight posts (hereherehereherehereherehere, and here) about Sarah Koenig's Serial Podcast, which deals with the 1999 prosecution of 17 year-old Adnan Syed for murdering his ex-girlfriend, 18 year-old Hae Min Lee. This post is about the fifth episode of the Serial Podcast: "Route Talk."  This episode deals with the prosecution's use of cell tower pings at trial to establish the general location of Adnan's cell phone on the day of Hae's murder. In turn, this post deals with the admissibility and discoverability of evidence regarding these pings.

Here's Sarah Koenig's description of the prosecution's use of cell tower pings at trial:

In the detective’s notes, Dana and I found a handwritten itinerary, dated March 18, 1999. So that’s three day’s after Jay’s second taped interview with police. This is the route Jay laid out for the cops. His entire driving day, on January 13. This is what we’re going to try to replicate, to see if it matches the call record from that day. Because, right? The prosecution’s story of the crime was mainly pinned to two things. Jay’s statements and the cell records. Adnan remembers that at his trial, the prosecution had a big blow up chart of the call record, the one listing thirty four calls made and received on Adnan’s cell phone that day, with blanks besides each call. Every time a witness identified a call on the list, the prosecutor would label it with a sticker....


Besides the calls themselves, they also had a list of all the cell towers that pinged each time a particular call came in or when out. "Sure," the prosecutor said, "you might have your doubts about Jay, but the call record doesn’t lie. Jay couldn’t possibly have known which towers were getting pinged when. He couldn’t fabricate that. It would be too crazy of a coincidence." So the cell towers, and the calls and Jay’s story, they way they all meshed, prosecutors argued, was irrefutable. Prosecutor, Casey Murphy said to the jury in her closing statement, "The most important thing for you to remember about Jay’s testimony is that it does not stand alone. It is corroborated." She added, "The cell phone records support those witnesses say, and the witnesses support what those cell phone records say." There’s no way around it. 

But is there?

Admissibility of Cell Tower Pings

Was evidence of the cell tower pings admissible at trial? In the episode, Sarah Koenig noted that

The Washington Post ran a story in June, for instance, with the headline, "Experts Say Law Enforcement’s Use of Cell Phone Records Can Be Inaccurate." Federal courts in Oregon and Illinois have ruled cell phone evidence inadmissible.

How accurate is this last claim? Somewhat. I believe that the Illinois case referenced in the Washington Post article is United States v. Evans, 892 F.Supp.2d 949 (N.D.Ill. 2012). Evans was a kidnapping case, and the prosecution sought to have an expert, Special Agent Joseph Raschke, offer expert opinion testimony about cell phone pings under the theory of granulization. According to the court,

To determine the location of a cell phone using the theory of granulization, Special Agent Raschke first identifies (1) the physical location of the cell sites used by the phone during the relevant time period; (2) the specific antenna used at each cell site; and (3) the direction of the antenna's coverage. He then estimates the range of each antenna's coverage based on the proximity of the tower to other towers in the area. This is the area in which the cell phone could connect with the tower given the angle of the antenna and the strength of its signal. Finally, using his training and experience, Special Agent Raschke predicts where the coverage area of one tower will overlap with the coverage area of another.

The purpose of Rachke's testimony would have been to prove that "calls placed from Evans's cell phone during the course of the conspiracy could have come from the building where the victim was held for ransom." This testimony, however, was never given because the court deemed it inadmissible under Federal Rule of Evidence 702, which states that

A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if:  

(a) the expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue;  

(b) the testimony is based on sufficient facts or data;  

(c) the testimony is the product of reliable principles and methods; and  

(d) the expert has reliably applied the principles and methods to the facts of the case.

Here's a condensed version of the court's rejection of Raschke's testimony:

Despite Special Agent Raschke's assurances, the court remains unconvinced that granulization theory is reliable. First, in determining the coverage overlap of the two towers used by Evans's cell phone on August 24, 2010, Special Agent Raschke assumed that Evans's cell phone used the towers closest to it at the time of the calls. But as previously discussed, there are a number of factors that could have caused Evans's phone to connect to these towers even though another tower was closer. For example, a building could have obstructed the phone's access to the closest tower or the call could have been rerouted due to network traffic. Special Agent Raschke acknowledged these factors but did not fully account for them in his analysis. Rather, he relied on his training and experience to estimate the coverage overlap between the two. Estimating the coverage area of radio frequency waves requires more than just training and experience, however, it requires scientific calculations that take into account factors that can affect coverage. Special Agent Raschke presented no scientific calculations and did not consider a variety of relevant factors. Although the call data records upon which he relied are undisputed, the link between those records and his conclusions is deficient....

Second, the granulization theory remains wholly untested by the scientific community, while other methods of historical cell site analysis can be and have been tested by scientists

Sounds pretty good for Adnan's case, right? Yes and no. The "no" is because subsequent cases have construed Evans pretty narrowly. Consider this excerpt from the opinion of the United States District Court for the District of Columbia in United States v. Marchado-Erazo, 950 F.Supp.2d 49 (D.D.C. 2013):

Mr. Machado–Erazo relies heavily on Evans from the Northern District of Illinois. On first reading, Evans appears to cast doubt on all cell site analysis. But closer reading demonstrates that the technique found objectionable in Evans was different from the techniques implicated in Davis, Jones, and this case. The testimony held unreliable and inadmissible in Evans was an agent's claim that a cellular call came from a specific location at which a kidnapping victim was being held. The agent attempted to identify the location within a narrow area based on the overlap of coverage from two cell towers, using an analysis the witness and the Evans court called the "granulization theory."...In contrast, S.A. Magnuson would not testify about an overlap area; he would testify to the sectors within which a call must have occurred....Mr. Machado–Erazo's reliance on Evans is thus unpersuasive.

While I don't have the trial transcript from Adnan's trial, I'm guessing that the cell tower expert in the case mostly testified that Adnan's cell phone was likely in a certain "sector" based on pings rather than at a particular location. And, as the above excerpt makes clear, several cases have found this testimony to be permissible. That said, there is mention in the podcast about how two pings at 7:09 P.M. and 7:16 P.M. on the night of the murder led the expert to conclude that Adnan's cell phone was in Leakin Park, which is where Jay said they were burying Hae's body at those times (and where Hae's body was found). Or did the expert merely say that the pings meant the cell phone was in the sector that contained Leakin Park? I really need to see the trial transcript before drawing any definitive conclusions about whether the expert testimony at Adnan's trial went too far.

What about the Oregon case? That case is Roberts v. Howton, 13 F.Supp.3d 1077 (D.Or. 2014), which I referenced in the introduction to the post. As noted, the case looks a lot like Adnan's case. There are, however, a few key differences. One of those differences is that the defendant in Roberts actually pled guilty to first-degree manslaughter pursuant to a plea agreement. This is interesting because part of Adnan's claim of ineffective assistance of counsel (IAC) is that he asked trial counsel about a plea deal several times, but she never pursued it with the prosecution.

Another important difference is that the "key witness" defense counsel didn't contact in Roberts was the person who ended up becoming the alternate suspect, and the defendant actually "ackowledge[d] that in 2002, trial counsel would not have known to focus on" the alternate suspect. By way of contrast, Adnan's claim that his trial counsel failed to contact Asia McLeanMcClain, a pretty obvious alibi witness, seems much stronger, as I noted here.

So, how did the defendant win in Roberts? The defendant presented the affidavits of Forensic Technologists Jeff Fischbach and Manfred Schenk, who noted that

the prosecution's cell tower analysis did not take into account variables including (1) the height of the tower (which suggested an engineered intent to cover a significant area); (2) call load (which may cause a call to relay from another tower); (3) the network of cell towers (rather than the signal of one particular tower); and (4) the cell phone provider's proprietary software.

And here's the court's conclusion on the issue:

It is difficult to evaluate the reasonableness of an attorney's investigation ten years after the fact, particularly given the fact that [trial counsel] has died and cannot explain any strategic reasons for his actions. However, the state record demonstrates that the defense team understood the importance of the cell tower evidence, studied the underlying call records themselves, and had been advised that many variables may impact the ability to track a caller's path of travel or precise location. Despite this knowledge, [trial counsel] failed to retain an expert to evaluate the technical call data "code" relied upon by the Verizon technician, or to make an independent evaluation of the information then available.

So, why doesn't Adnan's claim of IAC contain an argument that his trial counsel failed put up enough opposition to the State's cell tower evidence? Well, this is where things get weirder.

Discoverability of the State's Cell Tower Evidence

Here's what Sarah Koenig has to say about the introduction of the cell tower evidence at Adnan's trial:

Just a word about the cell tower testimony. It took two days and it was sort of a mess. Adnan’s defense attorney, Cristina Gutierrez claims she didn’t have all the cell record evidence, she didn’t have the cell tower map, she tries to get Waranowitz’s testimony thrown out, the judge nearly agrees with her, then prosecutor Kevin Urick ends up asking for a mistrial, which isn’t granted, and all this might sound like exciting courtroom fireworks, but it just-- I cant stress enough how tedious must have been for the jury.

Wow. Why did the judge nearly agree with defense counsel? Maryland Rule 2-402(a) states that

A party may obtain discovery regarding any matter, not privileged, including the existence, description, nature, custody, condition, and location of any documents or other tangible things and the identity and location of persons having knowledge of any discoverable matter, if the matter sought is relevant to the subject matter involved in the action, whether it relates to the claim or defense of the party seeking discovery or to the claim or defense of any other party. It is not ground for objection that the information sought is already known to or otherwise obtainable by the party seeking discovery or that the information will be inadmissible at the trial if the information sought appears reasonably calculated to lead to the discovery of admissible evidence. An interrogatory or deposition question otherwise proper is not objectionable merely because the response involves an opinion or contention that relates to fact or the application of law to fact.

This would clearly cover the cell record evidence and the cell tower map. See, e.g., Cole v. State, 835 A.2d 600 (Md. 2003) And, if the prosecution failed to disclose this key cell tower evidence, the sanction should have been that the prosecution could not present the expert testimony of Waranowitz. See, e.g., Rodriguez v. Clarke, 926 A.2d 736 (Md. 2007). At a minimum, the judge should have given the defense a continuance to prepare arguments against the cell tower evidence and/or to prepare its own accounting of the pings, such as the one that attorney Susan Simpson did here. Aside from Jay's testimony, the two Leakin Park pings were the most important pieces of evidence against Adnan at trial, and yet...

The judge ultimately deemed Waranowitz's testimony admissible. And then the PROSECUTOR moved for a mistrial? Huh. How does that make sense? The prosecutor got what he wanted. The only hypothesis that I can come up with is that defense counsel called him a liar in connection with the cell tower evidence. Interestingly enough, Adnan's first trial ended in a mistrial after a juror overheard a judge referring to defense counsel as a liar. But if the prosecutor was called a liar in this second trial, why wasn't another mistrial declared? Was the judge worried about the impact of a second mistrial?

A lot of this is speculation because I don't have the trial transcript. But I feel pretty solid in saying the following: First, if the prosecution didn't disclose much of the cell tower evidence, Waranowitz's testimony should have been deemed inadmissible or a continuance should have been granted. The failure to do either seems to be reversible error. Second, if the prosecution did disclose all of the cell tower evidence and defense counsel didn't realize she'd received it, that's ineffective assistance of counsel. If you look at Roberts, defense counsel in that case actually did prepare to rebut the prosecution's cell tower evidence; he simply didn't do enough. If Adnan's trial counsel didn't even know she had gotten the full cell tower evidence from the prosecution, that's IAC.



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Perhaps the reason there was a mistrial the first time and not the second time is because the first time the *judge* called Gutierrez a liar, while in the second trial *Gutierrez* called Urick a liar.

Posted by: DM | Dec 23, 2014 10:55:08 AM

Thank you so much for the informative posts. Many on the Serial subreddit seem to be under the impression that the cell tower records prove that those two evening calls originated in Leakin Park, but it's my understanding that, at most, the pings can only show what sector the phone must have been in at those times, a sector that would have included much more than just Leakin Park.

(A minor correction: Asia McClain's name is misspelled.)

Posted by: Bryan | Dec 26, 2014 2:05:15 PM

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