Commonwealth v. Landis, 89 A.3d 694

At 2:40 a.m. on April 4, 2010 troopers observed Daniel Landis weave, cross the double-yellow line twice, and veer toward the center line; they stopped his pickup.
Troopers smelled alcohol, administered a positive preliminary breath test, and observed signs of impairment; Landis failed one field-sobriety test.
Blood was drawn at 3:18 a.m. and tested once on an Avid Axsym enzyme assay; the machine reported 163.88 mg/dL (.164%).
The hospital technician acknowledged a 10% margin of error for the Axsym result; defense expert testified the assay is less reliable than gas chromatography and that .164% could range roughly .147–.180.
A jury convicted Landis of DUI (incapable) and DUI — highest rate (.16%+); trial court sentenced him and denied post-sentence relief and suppression. Landis appealed.

Issue	Landis's Argument	Commonwealth's Argument	Held
Whether the DUI — highest rate (.16% within 2 hours) verdict was against the weight of the evidence	Single blood draw and single test on an enzyme assay with a 10% margin of error made the .164% result unreliable; verdict shocks the conscience	Testing done at an approved facility, technician followed protocol; jury entitled to credit the reported .164%	New trial on the DUI — highest rate count. The court abused discretion by treating weight claim improperly and the record lacked a reasoned basis to treat .164% as reliably ≥ .16% given the uncontested 10% range
Whether the traffic stop should have been suppressed because troopers lacked reasonable suspicion or probable cause	Troopers lacked probable cause to stop for lane maintenance and lacked reasonable suspicion of DUI to justify an investigatory stop	Trooper stopped Landis for a lane violation under 75 Pa.C.S. §3309; suppression denial was proper	The Commonwealth needed to show probable cause for the lane-violation stop; suppression order vacated because the suppression court failed to file findings of fact and conclusions of law—case remanded for reconsideration under the proper standard

Commonwealth v. Karns, 50 A.3d 158 (discusses standard of review for weight-of-the-evidence challenges)
Commonwealth v. Rivera, 983 A.2d 1211 (Pa. 2009) (explains role of trial court in weight-of-the-evidence review)
Commonwealth v. Clay, 64 A.3d 1049 (Pa. 2013) (limits on trial court discretion in granting/denying new trials)
Commonwealth v. Feczko, 10 A.3d 1285 (en banc) (standard of review for suppression rulings)
Commonwealth v. Busser, 56 A.3d 419 (stopping for lane violations requires probable cause where the stop has no DUI investigatory purpose)
Commonwealth v. Sibley, 972 A.2d 1218 (distinguishes sufficiency vs. weight where test variability affects proof of BAC)
Commonwealth v. Widmer, 744 A.2d 745 (jury must find facts beyond a reasonable doubt)
Commonwealth v. Grundza, 819 A.2d 66 (requirement that suppression courts enter findings of fact and conclusions of law)