State v. Patton, 419 S.W.3d 125

Defendant Melvin R. Patton was convicted by a St. Louis jury of two counts of first-degree murder, first-degree assault, first-degree burglary, and three counts of armed criminal action; he received consecutive life sentences for murder.
The shootings occurred April 21, 2010; two victims died, a third survived, and the surviving victim plus the defendant’s son identified Patton as the shooter. A cellmate testified Patton confessed.
Patton claimed an alibi: he was sleeping at his cousin’s house in Cahokia, Illinois, the night of the shootings; witnesses (including Patton) corroborated this.
The State introduced historical cellular “cell site” records and a map showing which cell towers Patton’s phone connected to before, during, and after the murders to place him near the crime scene. A non-expert State witness testified about the connections.
Patton objected, arguing a Frye hearing and expert testimony were required to interpret cell site data; he also objected to admission of family photographs as inflammatory. The trial court admitted both the cell-site map/testimony and the photos.
On appeal, the court addressed (1) admissibility of historical cell site data and whether expert testimony/Frye were required, (2) prosecutor’s closing comment on that evidence (plain-error review), and (3) admission of family photographs; it affirmed the convictions.

Issue	Patton's Argument	State's Argument	Held
Whether Frye hearing required for historical cell-site data	Frye required because locating a phone from cell-site connections involves scientific techniques	Not scientific; mapping tower coordinates from records is non-scientific, so Frye not required	Frye not required for the limited act of plotting cell-site coordinates on a map (Frye applies only to scientific techniques)
Whether expert testimony was required to place phone relative to towers	Lay testimony was insufficient; expert needed to account for technical variables affecting which tower a phone uses	Lay presentation (map + basic explanation) sufficed	Error to admit opinion about phone location from lay witness; specialized analysis about signal variables is expert territory
Whether prosecutor's closing comments about cell-site evidence require reversal (unpreserved)	Comments improperly relied on the challenged evidence; plain error review	No plain error; overwhelming evidence of guilt made any potential prejudice harmless	Court declined plain-error review; overwhelming evidence precluded manifest injustice
Whether admission of family photographs was prejudicial	Photos were irrelevant and inflammatory; should be excluded	Photos were used to identify family members; probative for witness identification	Admission questionable but not outcome-determinative given overwhelming evidence of guilt

Elliott v. State, 215 S.W.3d 88 (Mo. banc 2007) (standard for abuse of discretion review)
State v. Davis, 32 S.W.3d 603 (Mo. App. E.D. 2000) (abuse of discretion definition)
State v. Manzella, 128 S.W.3d 602 (Mo. App. E.D. 2004) (cellular tower testimony and lay witness limits)
State v. Barriner, 34 S.W.3d 139 (Mo. banc 2000) (when improperly admitted evidence need not require reversal if other evidence is overwhelming)
State v. Foster, 68 S.W.3d 530 (Mo. App. E.D. 2001) (example of finding evidence overwhelming where eyewitness ID and confession exist)
State Bd. of Registration for Healing Arts v. McDonagh, 123 S.W.3d 146 (Mo. banc 2003) (discussion of Frye’s applicability; noted distinction between civil/criminal contexts)