Com. v. Gross, A., 241 A.3d 413

In October 2017 Ardell Gross shot and killed his uncle, Richard Smalley; Detective Dale Moore responded and interviewed Gross at the scene.
Moore administered a pre-arrest portable breath test (PBT) to Gross; a screenshot later produced showed a .213 BAC, but Moore did not report the PBT in his police report.
Moore had previously investigated (but did not charge anyone in) an alleged sexual assault of Gross about 8–9 years earlier; the assailant in that case was not Smalley.
The Commonwealth moved in limine to exclude any mention of the prior sexual assault and the PBT results; the trial court granted both motions.
At trial Moore testified Gross had been drinking but that he was "not overly concerned" about Gross’s intoxication; Gross objected that this opened the door to PBT evidence.
Gross was convicted of first-degree murder and sentenced to life; on appeal he argued the court erred by excluding the PBT and the prior sexual-assault evidence and by finding the Commonwealth had not opened the door to the PBT.

Issue	Commonwealth's Argument	Gross's Argument	Held
Admissibility of PBT results (motion in limine)	PBTs are per se inadmissible at trial and unreliable; authorized only for field probable-cause screening	PBT was relevant to a voluntary-intoxication defense and to show Moore hid a .213 result	Exclusion affirmed: Marshall/Brigidi control; defendant failed to lay judicial foundation for admission; PBT properly precluded
Did Commonwealth "open the door" to PBT by eliciting Moore’s testimony about intoxication	Moore’s testimony that he was not "overly concerned" did not open the door to otherwise inadmissible PBT results	Moore’s testimony created a misleading impression; cross should have been allowed to ask why he gave the PBT and concealed the result	No opening of the door; even if opened, exclusion was harmless beyond a reasonable doubt; ruling affirmed
Exclusion of evidence about Gross’s prior sexual assault and Moore’s prior investigation	Prior assault was collateral, remote in time, and would confuse/ mislead the jury; not relevant to elements of murder	Prior assault and Moore’s failure to investigate were probative of Moore’s bias and of why Gross did not call police; relevant to intent/ mindset	Exclusion affirmed: evidence was only slightly probative, collateral, and risked confusing the jury; trial court did not abuse discretion

Commonwealth v. Marshall, 824 A.2d 323 (Pa. Super. 2003) (PBT results are inadmissible at trial; devices approved only for field screening)
Commonwealth v. Brigidi, 6 A.3d 995 (Pa. 2010) (statutory/administrative approval of PBTs limited to probable-cause screening; Crimes Code prosecutions require established judicial foundation for PBT admission)
Commonwealth v. Ward, 605 A.2d 796 (Pa. 1992) (accused has right to present relevant evidence unless excluded by evidentiary rule)
Commonwealth v. Boczkowski, 846 A.2d 75 (Pa. 2004) (limits on impeaching witnesses with collateral matters)
Commonwealth v. Nypaver, 69 A.3d 708 (Pa. Super. 2013) ("opening the door" doctrine: proponent may introduce otherwise inadmissible evidence to refute a false impression)