State v. Carrillo, 2017-NMSC-023

Background

On Dec. 4, 2011, Christopher Kinney and Lyndsey Frost were found shot in a parked pickup in Albuquerque; physical evidence included shell casings, projectiles, and Kinney’s cell phone.
Police later detained Carlos Carrillo after a nearby report of someone breaking into a car; a witness saw him with a gun at that incident and police found heroin and a cell phone on him.
Kinney’s phone contained many calls/texts between Kinney and Carrillo in the early-morning hours; cellphone records showed numerous calls between them overnight and connections to towers near Old Town/Downtown around the time of the killings.
State charged Carrillo with multiple counts including murder, tampering with evidence, breaking and entering, and possession; trial resulted in convictions and two merged life sentences plus additional years.
At trial, the State presented testimony from two phone-record witnesses: a carrier records custodian (Cabrera) who explained the records and testified about how cell towers operate, and a mapping vendor (Tan) who produced call-location maps; defense objected that technical testimony required a qualified expert.
The New Mexico Supreme Court held that testimony about the contents of phone business records and tower locations was admissible via the records custodian, but technical explanations of how towers determine location required a qualified expert; the court found the lack of expert qualification for that technical testimony was error but harmless given the properly admitted records and other evidence.

Issues

Issue	State's Argument	Carrillo's Argument	Held
Admissibility of cell-phone evidence / whether lay witnesses may testify about cell-tower operation	Records custodian may testify to contents of call detail and tower-location records; nontechnical mapping testimony need not be expert	Technical explanation of how towers determine phone location required a qualified expert under Rule 11-702	Contents of business records and tower-location maps admissible via custodian (Rule 11-803(6)); but technical testimony about tower operation required expert — admission without expert was error but harmless
Preservation of objection to Tan’s testimony	State: no abuse — testimony was nontechnical; trial counsel had opportunities	Carrillo: motion in limine and general objections preserved error	Objection to Cabrera preserved; objection to Tan not preserved (trial objection not made), so Tan’s testimony reviewed only for plain error and not found plain
Sufficiency of the evidence (identity and other elements)	Phone records, texts, tower connections, witness seeing Carrillo with a gun, and inconsistent statements supported identity and other elements	Insufficient proof that Carrillo committed the murders or that evidence supported tampering/breaking-and-entering convictions	Viewing evidence in light most favorable to verdict, a rational juror could find Carrillo guilty of the murders, tampering with evidence, and breaking-and-entering; convictions upheld
Prosecutorial misconduct / cumulative error	State: no prior exclusion order; limiting instruction was given; no misconduct	Carrillo: State repeatedly tried to introduce excluded statements by witnesses	No preserved claim of prosecutorial misconduct in record; no evidence of prior exclusion order; limiting instruction given; no fundamental error; cumulative-error claim rejected

Key Cases Cited

State v. Torres, 127 N.M. 20, 976 P.2d 20 (N.M. 1999) (expert-admissibility framework and standards)
State v. Alberico, 116 N.M. 156, 861 P.2d 192 (N.M. 1993) (trial court discretion over expert/scientific evidence)
United States v. Yeley-Davis, 632 F.3d 673 (10th Cir. 2011) (cell-tower operation explanations are expert territory)
United States v. Hill, 818 F.3d 289 (7th Cir. 2016) (technical nature of how cell networks and handoffs work)
Burnside v. State, 352 P.3d 627 (Nev. 2015) (distinguishing admissible nontechnical tower-location testimony from expert location analysis)
Blurton v. State, 484 S.W.3d 758 (Mo. 2016) (lay testimony OK for tower locations but not for precise pinpointing)
Collins v. State, 172 So.3d 724 (Miss. 2015) (call-detail/tower-location description may be lay testimony when based on personal knowledge)
State v. Silva, 144 N.M. 815, 192 P.3d 1192 (N.M. 2008) (tampering intent requires direct evidence or overt act from which intent may be inferred)
State v. Leyba, 289 P.3d 1215 (N.M. 2012) (harmless-error analysis for nonconstitutional evidentiary errors)
State v. Tollardo, 275 P.3d 110 (N.M. 2012) (standards for prejudicial impact of improperly admitted evidence)