De H Nguyen v. the State of Texas, 03-23-00301-CR

De H Nguyen was convicted of felony murder in connection with the 2015 killing of Samantha Miranda in New Braunfels, Texas.
The investigation relied heavily on a "geofence" warrant, which enabled law enforcement to obtain location data from Google for cellphones present in defined geographic areas during a specific time surrounding the murder.
The police used the geofence data to narrow down suspects, ultimately leading them to Nguyen's Google account and associated data, which placed him at the scene.
Nguyen's known associate, Joseph Austin, testified that Nguyen planned and participated in the robbery and subsequent killing of Miranda.
The trial court denied Nguyen’s motion to suppress the geofence evidence and rejected his argument that accomplice testimony was insufficiently corroborated.
On appeal, Nguyen challenged both the denial of his suppression motion and the admissibility of accomplice testimony.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Validity of Geofence Warrant	Geofence warrant was a general, unconstitutional search; lacked particularity and probable cause	Warrant was sufficiently particularized and supported by probable cause	Warrant valid and search was constitutional
Accomplice Testimony	Insufficient corroborating evidence independent of accomplice’s testimony	Non-accomplice evidence (location data, admissions, surveillance, etc.) sufficed	Evidence corroborated; testimony admissible

State v. Martinez, 570 S.W.3d 278 (Tex. Crim. App. 2019) (standard of review for suppression motions)
State v. McLain, 337 S.W.3d 268 (Tex. Crim. App. 2011) (deferential review of warrant issuance)
State v. Duarte, 389 S.W.3d 349 (Tex. Crim. App. 2012) (probable cause standard)
Adkins v. State, 418 S.W.3d 856 (Tex. App.—Houston [14th Dist.] 2013) (burden on defendant to prove unreasonableness of a warrant-based search)
Bonds v. State, 403 S.W.3d 867 (Tex. Crim. App. 2013) (magistrate deference and reasonable inference in warrant review)
Reed v. State, 744 S.W.2d 112 (Tex. Crim. App. 1988) (accomplice-witness rule for corroboration)
Brown v. State, 270 S.W.3d 564 (Tex. Crim. App. 2008) (standard for corroboration of accomplice testimony)