He also claims that the trial judge abused her discretion when she admitted in evidence an 'arrest booking form' that contained the defendant's photograph and a document from the Boston Municipal Court showing the defendant's previous conviction of possession of a class B drug with intent to distribute. The defendant's claim regarding the certificate of analysis is controlled in all material respects by Commonwealth v. Casali, 459 Mass. 139, 147 (2011). Here, as in Casali, a police officer testified regarding his training in identifying cocaine and also testified that he had field tested the substance and the results were positive for cocaine.

See Commonwealth v. Fernandez, 458 Mass. 137, 151 n. 20, 934 N.E.2d 810 (2010) (“no appellate case from Massachusetts has accepted as reliable field test results, regardless of the purpose for which they are offered”); Commonwealth v. King, 461 Mass. 354, 358–359, 960 N.E.2d 894 (2012) (police field test not dispositive in absence of testimony on officer's expertise and type of field test kit used); Commonwealth v. Billings, 461 Mass. 362, 364–365, 960 N.E.2d 900 (2012) (police field test not sufficient without testimony on officer's expertise and testimony on actual test results). Compare Commonwealth v. Connolly, 454 Mass. 808, 831, 913 N.E.2d 356 (2009) (field tests one factor in nullifying effect of drug certificates in circumstances where testing officers had seventeen and thirteen years, respectively, of narcotics investigation experience and both were subject to cross-examination); Commonwealth v. Casali, 459 Mass. 139, 147, 943 N.E.2d 936 (2011) (police field test rendered drug certificates harmless beyond reasonable doubt only in combination with defendant's own testimony that seized substances were heroin and marijuana, defense counsel's concession on that point, and evidence that defendant was admitted to hospital for symptoms of heroin withdrawal one day after crime). Given that a field test may not meet the constitutional harmless error standard, a fortiori, a lay taste test—even when conducted by an experienced cocaine user—does not meet the grade of proof required to render the error in admitting the drug certificates harmless beyond a reasonable doubt.