THE MAJORITY OF CASES WHERE PHYSICAL APPEARANCE IS RELEVANT TO REASONABLE CAUSE DEAL WITH OFFENSES THAT INCLUDE AN ALTERED PHYSICAL CONDITION AS AN ELEMENT OF THE CRIME. POLICE OFFICERS USUALLY OBSERVE THE APPEARANCE OF A SUSPECT AFTER TEMPORARY DETENTION. SECRETIVE OR CLANDESTINE FURTIVE ACTS OF A SUSPECT MAY BE TAKEN INTO ACCOUNT BY OFFICERS EITHER WHEN THE ACTS CONSTITUTE A REACTION BY A SUSPECT UPON SIGHTING OFFICERS OR WHEN ACTS ARE OBSERVED WITHOUT A SUSPECT'S KNOWLEDGE. THE USE OF FURTIVE ACTS IN DETERMINING REASONABLE CAUSE TO ARREST IS GENERALLY BASED ON THE THEORY THAT A SUSPECT HAS A NATURAL IMPULSE TO HIDE ANY CONTRABAND WHEN HE OR SHE IS CONFRONTED BY LAW ENFORCEMENT OFFICIALS. REGARDLESS OF THE DIFFERENT TYPES OF RESPONSES OR REFUSALS INVOLVING EVASIVE STATEMENTS, MOST COURTS MAINTAIN THAT A SUSPECT IS NOT COOPERATING WITH THE POLICE IN MAKING SUCH STATEMENTS. MERE FLIGHT IS INSUFFICIENT TO JUSTIFY A WARRANTLESS ARREST. THE NATURE OF FLIGHT IS CRUCIAL WHEN A REVIEWING COURT SCRUTINIZES THE REASONABLE CAUSE DETERMINATION, AND THE REQUIREMENT THAT FLIGHT BE SUBSTANTIALLY CONTEMPORANEOUS WITH THE CRIME ENCOMPASSES MORE THAN A TEMPORAL ELEMENT. THERE MUST ALSO BE A SUFFICIENT NEXUS BETWEEN A SUSPECT'S FLIGHT AND THE COMMISSION OF A PARTICULAR CRIME. COURTS SHOULD EMPHASIZE AT LEAST THREE DIFFERENT REVIEWING TECHNIQUES TO TEST REASONABLE CAUSE: (1) INVESTIGATE SUSPICIOUS ACTS OF A DEFENDANT WITH REGARD TO THE ATTENUATION OF THOSE ACTS AND THE PROBABILITY THAT A CRIME HAS BEEN COMMITTED; (2) EVALUATE THE CAUSE OF SUSPICIOUS ACTS AND (3) ANALYZE THE POLICE PRACTICE OF EXTENDING THE TEMPORARY STOP OF A SUSPECT UNTIL THE POLICE SATISFIED. CASE LAW IS CITED. (DEP)