The officers training and experience defense

We do not seek to minimize the experience gained through
years serving on the police force. Quite to the contrary, we
recognize that many officers, particularly those with specialized
training, are able to recognize trends and methods in the
commission of various crimes. For instance, an officer who
has specialized in drug crimes may be more suspicious that a
package contains illegal narcotics because of the form of
packaging used to conceal those drugs. He or she may
recognize criminal activity where a non-police citizen may not.
However, a court cannot simply conclude that probable cause
existed based upon nothing more than the number of years an
officer has spent on the force. Rather, the officer must
demonstrate a nexus between his experience and the search,
arrest, or seizure of evidence. By doing so, a court aware of,
informed by, and viewing the evidence as the officer in
question, aided in assessing his observations by his
experience, may properly conclude that probable cause
existed. This is true even where the court may have been
unable to perceive the existence of probable cause had the
court viewed the same evidence through the eyes of a
reasonable citizen untrained in law enforcement.

The Dunlap majority characterized as erroneous the Superior
Court’s use of training and experience as a “stand-alone factor” and stated: ‘[t]o be clear,
we hold that … a police officer’s training and experience is not a probable cause factor as
in the Lawson sense.” Commonwealth v. Dunlap, 941 A.2d 671 (Pa. 2007),