Reasonable suspicioun is reqauired for a terry stop when its a regular law that they have suspicioun of being violated.
Whren allows a pretextual stop on probable casue of a traffic law. (even if what they are really after is a more serious crime)
whether these combine to mean that if its a prextexual stop all you need is reasonable suspicion of a "traffic' law is actually not yet decided by the suspreme court and is the subjeect of..
a recent md high cour tdecision struggled with this issue: in state v williams 934 A.2d 38
it devotes a long essay to the question of when the pretext is only a traffic law and not a regular law..whehter you need resonable suspicion or probable cuase.
the majority in line with the majority of courts belive that it is reasonable suspicion even when the when pretext is only a traffic law and not a drug law or somthing.
United States v. Sanchez-Pena, 336
F.3d 431 (5th Cir. 2003); United Sta tes v. Hill, 195 F.3d 258, 26 4 (6th Cir. 1999); United
States v. Navarette-Barron, 192 F.3d 786, 79 0 (8th Cir. 1999); United States v. Lopez-
Soto, 205 F.3d 1101 (9th Cir. 2000); United States v. Chanthasouxat, 342 F.3d 1271 (11th
Cir. 2003); State v. Chavez, 668 N.W .2d 89 (S.D . 2003); State v. Bohannon, 74 P.3d 980
(Haw. 2003); and cf. State v. Crawford, 67 P.3d 115 (K an. 2003).
so that appears to be the law in the 8th 9th 6th 11th and 5th circuits at least.
also in the context of this analysis of saying that when doesnt meant that PC is nesssary when its a trafic law pretext...the 9th cir case United States v. Lopez-
Soto, 205 F.3d 1101 (9th Cir. 2000) says that:
"Moreover, none of our sister circuits, either before or after Whren, has concluded that a traffic stop must be justified by more than reasonable suspicion. Where the facts before the court would satisfy both reasonable suspicion and probable cause, many of the more recent cases echo the language in Whren and simply analyze the facts for probable cause, see, e.g., United States v. Sanders, 196 F.3d 910, 913 (8th Cir.1999); United States v. Brown, 188 F.3d 860, 864 (7th Cir.1999); United States v. Jones, 185 F.3d 459, 464 (5th Cir.1999); United States v. Wellman, 185 F.3d 651, 656 (6th Cir.1999), but none of these cases suggests that probable cause is the minimum threshold for constitutionally permissible police action in making a traffic stop. In fact, some circuits have explicitly held, post- Whren, that reasonable suspicion is all the Fourth Amendment requires. See, e.g., United States v. Hill, 195 F.3d 258, 264 (6th Cir.1999); United States v. Navarrete-Barron, 192 F.3d 786, 790 (8th Cir.1999); United States v. Ozbirn, 189 F.3d 1194, 1197 (10th Cir.1999). We join those circuits and reaffirm*1105 that the Fourth Amendment requires only reasonable suspicion in the context of investigative traffic stops."
so while the suprem court hasnt decidde whehter a whren stop on a pretext of a traffic law only requires PC or RAS...the circuit courts are almost unanomusly going the resonable suspicion way...which is logical since whren doesnt explicitly reverse terry.