Ebeneser Benny Morones v. State, 09-16-00318-CR

Police pursued a white Cadillac; officers testified Morones fired multiple rounds at pursuing officers during the high-speed chase and after exiting the interstate.
The Cadillac crashed; officers recovered multiple firearms, drugs, scales, ammunition, and an M1 carbine; an M1 carbine was later found on Morones.
Dawn Laporte, a Firearms Examiner II, testified that three items were fired from the M1 carbine based on toolmark/firearm examination.
Defense objected under Texas Rule 403 and Daubert (702) that toolmark identification lacks a known error rate and is subjective; court overruled the objections and admitted Laporte’s testimony and exhibits.
Morones was convicted of unlawful possession of a firearm by a felon, evading arrest with a vehicle, aggravated assault on a public servant, and possession of a controlled substance with intent to deliver; sentence: life imprisonment.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Admissibility of toolmark/firearm identification evidence	State: Laporte is qualified; methodology is peer-reviewed, generally accepted, and validated by studies and proficiency testing	Morones: Technique is scientifically unreliable without known error rate; subjective and unfairly prejudicial under Rule 403 and Daubert/Rule 702	Court: Even assuming error, any error was harmless; admission did not affect substantial rights, conviction affirmed

Coble v. State, 330 S.W.3d 253 (Tex. Crim. App. 2010) (standard: abuse of discretion review for admission of expert testimony)
Schmutz v. State, 440 S.W.3d 29 (Tex. Crim. App. 2014) (definition of when a nonconstitutional evidentiary error affects substantial rights)
Motilla v. State, 78 S.W.3d 352 (Tex. Crim. App. 2002) (overwhelming evidence of guilt can show harmlessness of erroneous admission)