July-August 2009

A primer on wiretaps, pen registers, and trap and trace devices

Texas investigators and prosecutors rarely use these tools, but they can be incredibly handy in certain situations. Here’s how to obtain and employ them in partnership with law enforcement.

Jeff Strange

Assistant District Attorney in Fort Bend County

The purpose of this article is to generally discuss the utility of wiretapping, the use of pen registers and trap and trace devices, and how to obtain them.

    Wiretapping has become a hot-button issue with the political pundits on cable news shows but has a legitimate law enforcement function. The cellular telephone now plays an important role in just about everyone’s life; thus, police are now more frequently popping up in our offices seeking assistance with pen registers. A prosecutor who wishes to stay ahead of the curve definitely has to adapt his tool belt to the changing times.

    Wiretaps are infrequently used in Texas; only four were authorized in 2007, all in Harris County. By comparison, Los Angeles County alone was granted 291 of California’s 660 wiretap orders, while state prosecutors in Arizona were granted 35 wiretaps in 2007, and Tennessee courts signed 19 wiretap orders.1

    Obviously, different regions of the country have different law enforcement needs and practicalities that dictate the directions of their criminal investigations. It is probably also fair to suggest that different regional law enforcement cultures exist. For example, authorities on the East Coast have long use wiretaps and “bugs” fighting organized crime; thus, they are more comfortable with the process and have somewhat streamlined it.

    One area where wiretaps are consistently useful is in narcotics investigations. Of the 2,208 wiretaps authorized nationwide, 1,792 were used in drug cases; such investigations lend themselves to wiretaps as the information gleaned can be used to identify and go up a chain of command. They are also very helpful in locating drug and cash caches. As narcotics investigations are proactive and not strictly reactionary, they allow more detailed pre-planning. Undercover officers, informants, and controlled buys traditionally provide the basis of the probable cause necessary to obtain a wiretap. Pen register and trap and trace information focus investigators on the relevant telephones and potential co-conspirators.

    Each of Texas’ nine judicial regions has a designated district court judge authorized to sign interception orders. Statutorily, our ability to seek a wiretap is limited to the offenses of capital murder, murder, child pornography, and felony drug offenses other than possession of marijuana.2 All four of the wiretaps authorized by Texas judges in 2007 were for narcotics offenses. However, wiretapping has utility beyond the traditional narcotics investigation.

    One example is the recent tracking of Brandon Wayne Robertson, who killed decorated DPS Trooper James Burns. Robertson sought refuge in the dense East Texas woods of Cass County. Texas Rangers had learned from an informant that Robertson had holed up in an abandoned methamphetamine lab. Authorities had a warrant for his arrest and were contemplating how best to serve it. Robertson, a former police officer and trained survivalist, was a dangerous adversary in this rugged environment.

    A trap and trace and pen register order was signed by a local judge providing Rangers with the phone numbers of all incoming and outgoing calls involving Robertson’s cell phone. With the assistance of local prosecutors, an emergency wiretap order was signed for the criminal’s cell phone. DPS investigators listened in as Robertson detailed his plans to resist capture, with deadly force if necessary. Robertson vowed in one intercepted call not to be taken alive.

    Police overheard Robertson stating that he was going to abandon his hideout in an attempt to leave the area, at which time he was tracked and surrounded just outside of Linden. A man of his word, Robertson turned his weapon on himself and ended his life. Because police knew of his intentions ahead of time, they could take precautions to minimize danger to themselves and any bystanders.

Procuring a wiretap

The Texas Department of Public Safety (DPS) is the only agency authorized to possess, install, and operate wiretapping equipment pursuant to State law.3 The DPS Technical Unit, located at the main headquarters in Austin, has four rooms for monitoring and recording wiretaps. Each room can monitor two telephones apiece. Under Texas law, the application for a wiretap must be made by the elected district attorney, criminal district attorney, or county attorney with felony jurisdiction4 at the request of the head of a law enforcement agency. Before an application may be sought, the director of the Department of Public Safety must approve the project in writing.5

    Anyone considering seeking a wiretap should get folks in DPS’s technical unit involved as soon as possible. They will provide valuable assistance in all aspects of the effort, starting with the preparation of the wiretap application, which should track art. 18.20 §8 of the Texas Code of Criminal Procedure. Be sure to review this statute with the officer serving as affiant; the section itself is a good organizational tool when preparing both the application and affidavit. The reviewing judge should be able to read both with his codebook open and stay on track.

    The affidavit must demonstrate that probable cause for one of the enumerated offenses exists and that the proposed wiretap will likely intercept relevant communications. When possible, it is necessary to identify the target of the wiretap and the location of the relevant telephone. Finally, the reviewing judge must be satisfied that traditional investigative methods have been tried and failed or would be too dangerous or impractical. Intercepting communications is supposed to be a tightly controlled, meticulously documented last resort.

    A court may not sign a wiretap order granting a fishing expedition or a Hail Mary pass when all else has failed. Go into the process ready to detail a practical plan. DPS will not commit resources unless officials there can see a method to your madness. A wiretap can cost in the hundreds of thousands of dollars for the logistics and police overtime: A tap must be monitored by two members of the investigative agency at all times. Additionally, a pen register must be obtained before a wiretap can start monitoring conversations. There must also always be a member of DPS present when communications are actually being intercepted.

    While the wiretap must be monitored at DPS headquarters in Austin, the technical capability exists to provide a remote, secondary monitoring location at the investigating police agency. A prosecutor assisting in the effort should be available to prepare grand jury subpoenas for telephone records and applications for pen registers as the investigation expands. The wiretap will provide raw data of the phone numbers involved in the phone calls. The subscriber information is obtained via good old-fashioned shoe leather.

The benefits

The utility of a wiretap when investigating an ongoing criminal enterprise is obvious. Police get to listen to what the crooks are saying while they are committing the crime. This is why wiretaps are used predominately in drug investigations. A wiretap is more difficult to obtain for a completed crime, and their use in cold cases will require imagination, planning, and sometimes pure dumb luck. The major obstacle is demonstrating to the reviewing judge that the relevant parties will likely continue to communicate relevant information about the offense via the telephone. Criminals tend to split up and keep their mouths shut after committing a crime, but that’s not always true.

    In 2005, for example, Sugar Land police were investigating a 2003 murder-for-hire in which two members of Thomas Bartlett Whitaker’s family were shot to death as they entered their home. (Read more about this investigation and trial in the September-October 2007 issue of this journal, available at www.tdcaa.com/node/1448.) Police suspected that Whitaker had induced his two roommates to commit the murder so the three of them could split the eventual inheritance. Detectives had meticulously documented the times they had initiated and terminated several interviews with Chris Brashear and Steven Champagne, the suspected shooter and getaway driver, respectively. A review of the three suspects’ cell phone records revealed that they called each other almost immediately after police investigators left their company. On a couple of occasions, after the flurry of phone calls, the suspected shooter, Chris Brashear, contacted police to change or explain the details of his story.

    The Sugar Land wiretap application proposed to combine the wiretap with the issuance of grand jury subpoenas for Brashear, Champagne, their parents, and their girlfriends.6 Detectives asserted that the suspects would return to their pattern of contacting each other to discuss the crime when it was clear the investigation was renewed.7

    When such an effort is contemplated, it is important for police and prosecutors to work together to develop a strategy well before the wiretap application is sought. As reluctant as police can be to involve prosecutors in their investigations early on, investigative strategy can be tailored to develop the probable cause for a wiretap. In the Sugar Land case, police sought to obtain incriminatory statements from Champagne to use as leverage to induce his cooperation in prosecuting Brashear and Whitaker, both of whom played a more active role in the murders. The theory articulated in the wiretap application was developed by comparing investigators’ notes with the suspects’ cell phone records. Always remember that before the Department of Public Safety will commit valuable resources, the wiretap must have a clearly defined goal. Be prepared to articulate how the proposed wiretap will advance the ball toward solving the crime.

Other rules

As with the Robertson case (the murderer hiding out in the woods), a wiretap may be granted on an emergency basis by seeking the verbal approval of the appropriate “wiretap judge.”8 An appropriate application and affidavit must be filed with the court within 48 hours after the wiretap is initiated.9 Emergency wiretaps are appropriate in response only to an immediate life-threatening situation and may be initiated only by Department of Public Safety officials or officers specially trained to deal with life-threatening situations.

    Any wiretap order is good for 30 days; however, an application for extensions in 30-day increments may be filed. Each and every call, pertinent to the investigation or not, must be carefully documented and a report must be filed with the authorizing court every 10 days during the wiretap’s pendency. The prosecutor must assist with this report and develop a working relationship with the reviewing judge. The report must detail the number of calls intercepted, the number of pertinent and non-pertinent calls, and the duration of the recording. If the judge cannot see that the investigation is making satisfactory progress, the wiretap may be terminated before the expiration of 30 days.

    A wiretap order does not give police carte blanche to listen to the entirety of each and every intercepted phone conversation. Police may listen at the beginning of each conversation to determine if it is pertinent to the subject of the investigation (called “minimization”). If it is, police may continue to monitor and record the conversation. If after listening for a few minutes the call is deemed non-pertinent, police are required to minimize or stop monitoring the conversation. Failure to minimize could result in suppression. The prosecutor must be involved in determining minimization protocols, training officers, and making sure this process is followed.

    Crooks quickly became familiar with the law of minimization and would frequently spend the first five minutes of each conversation discussing the weather or some other innocent subject, only to discuss business after police had minimized. Police are now allowed to spot-monitor calls after minimizing. After the call is minimized, they may briefly check in to determine if the call has become pertinent. They may repeat this process on a regular basis during the call’s duration, and police are allowed more latitude at the beginning of a wiretap. After conversation patterns are established, police are expected to be more efficient in their minimization practices.

    Each monitored phone call or portion thereof must, under the statute, be recorded.10 Additionally, the recordings must be preserved, and a copy will ultimately be filed with the court at the termination of the wiretap. Keep in mind that the recordings will not just produce evidence that the State may use in court. The recordings will also show the monitoring officer’s minimization practices, providing fodder for possible suppression of the wiretap.

Pen registers and trap and trace devices

A pen register or trap and trace device, unlike a wiretap, does not require a finding of probable cause.11 The application must simply state under oath that the installation and use of the device will likely produce information material to an ongoing investigation. The application must further identify the telephone subscriber and the relevant phone number and carrier. The application may be reviewed by a district court judge in the jurisdiction of the requesting agency, the location of the device, telephone subscriber, or communications carrier.12

    Should a pen register or trap and trace appear to be useful in an ongoing investigation, it is a good idea to seek the assistance of a local Texas Ranger or DPS investigator. Any peace officer may apply for a pen register, but the application must be filed by the appropriate elected prosecutor unless the requesting peace officer is employed by the Texas Department of Public Safety or is “commissioned by the department.”13

    Not only does a pen register show outgoing and incoming phone numbers, but if tracking a cellular phone, it also identifies the cellular antenna and sector that the cell phone is using at the beginning and end of the call. Thus, a pen register has some utility tracking people, usually people with warrants for their arrest. A pen register is also a good source of investigative intelligence. If a known suspect and his phone are identified, a pen register can provide the identities of potential co-conspirators. After a completed crime, if a known suspect is on the run, a pen register helps identify potential destinations, allowing police to prepare a warm welcome for the wayward crook.

    Like wiretaps, pen registers and trap and trace devices can be installed on an emergency basis, again, allowing officers to obtain verbal authorization and file the appropriate application within 48 hours.14 Like a wiretap, only specially trained officers may install a pen register during emergencies. A pen register is also not cheap. A police agency wishing to use this technology will invest between $20,000 and $30,000 in equipment and specialized training. Additionally, telephone companies typically charge an average of $600 per target to conduct pens.

    A pen register or trap and trace order is good for 60 days but may be extended for another 60 days upon a showing of good cause.15 The pen register, like a wiretap, must be routed through DPS headquarters but may be monitored by the requesting police agency remotely at the location of the investigation. The pen register is less onerous to monitor than a wiretap as conversations are not monitored and recorded. Unless pen register is granted for an emergency, there is no further necessity of documenting the results with the court.


The decision to intercept telephone conversations is not one to be made on a whim or without knowing what it entails. We as prosecutors need to change with the times and the technology to track and trace criminals. They use cell phones, and cell phones contain and transmit information useful in the investigations of the crimes they commit. How we assist police in the effort is really limited only by our imagination. ✤

Editor’s note: The author wishes to thank Sgt. Breck McDaniel of the Houston Police Department, Texas Ranger Brandon Davis, and Captain Doug Kunkle of the Texas Department of Public Safety for their expertise, input, and assistance with this article.


1 All statistics are provided by the 2007 Wiretap Reports, Administrative Office for United States Courts.
2 Tex. Code Crim. Proc. art. 18.20 §4. This statute has been expanded over the years to be more inclusive. Originally, wiretapping was an option only for narcotics-related offenses.
3 Tex. Code Crim. Proc. art. 18.20 §5(a). This statute of course does not apply to federal agencies, several of which have the ability to conduct wiretaps.
4 Tex. Code Crim. Proc. art. 18.20 §1 (8).
5 Tex. Code Crim. Proc. art. 18.20 §6.
6 Bart Whitaker had fled and was later arrested in Mexico.
7 All three suspects were arrested and convicted. Thomas Bartlett Whitaker is currently on Texas’ Death Row.
8 Read and be familiar with Tex. Code Crim. Proc. art. 18.20 §8A.
9 Tex. Code Crim. Proc. art. 18.20 §8A(d)(2).
10 Tex. Code Crim. Proc. art. 18.20 §10.
11 Uresti v. State, 98 S.W.3d 321 (Tx. App.—Houston [1st District] 2003); Smith v. Maryland, 442 U.S. 735 (1979) ; see also Richardson v. State, 865 S.W.2d (Tex. Crim. App., 1993).
12 Tex. Code Crim. Proc. art. 18.21 §2(a).
13 These are officers with the Dallas, Houston, Fort Worth, Austin, San Antonio, and El Paso Police Departments and the Harris County Sheriff’s Department.
14 Tex. Code Crim. Proc. art. 18.21 §3.
15 Tex. Code Crim. Proc. art. 18.21 §2(f).