In contrast, by Grits' count federal judges approved 104 wiretaps in Texas during calendar year 2011, of which 102 were narcotics cases and two related to "corruption." About four in 10 (41) federal wiretaps in Texas resulted in arrests, but several involved dozens of people. The largest, out of Texas' Northern District, resulted in 41 drug convictions. Motions to suppress wiretap evidence succeeded just six times and were denied 16 times.
In all, federal authorities arrested 411 people in Texas in 2011 based on wiretaps resulting in 164 convictions, including 29 arrests and 21 convictions in corruption cases. (Data compiled from these tables, pp. 90-99, large pdf.)
I'm not sure why Texas judges are bucking the national trend of approving more wiretaps than the feds, but by these data the feds in Texas are making up quite a bit of the difference, particularly in the Western District on narcotics cases.
RELATED: Via TDCAA, see "A primer on wiretaps, pen registers and trap and trace devices," which provides a bit of additional process detail regarding state-level wiretaps. "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," wrote Fort Bend ADA Jeff Strange in 2009.
The TDCAA article also give some interesting background on pen registers and trap and trace devices, use of which is not documented in the US Courts wiretap report:
A pen register or trap and trace device, unlike a wiretap, does not require a finding of probable cause. 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.
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.”
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.