A319
Air Traffic Control Fully Certified
Communication Breakdown
ATC Issue All Types; Conflict NMAC; Deviation / Discrepancy - Procedural Clearance
General None Reported / Taken
Procedure; Human Factors
Advised pilot to 'descend via the KEPEC3 expect after CLARR maintain 130'. He read it back correctly but descended below the MISEN crossing restriction; which is FL240. Another Controller called me to let me know the low sector was open. When I noticed what he was talking about I questioned the pilot and he said he thought I gave him the descent clearance to 130. I checked the tapes and he read it back correctly. I normally do not give that clearance (descend via except) but I was in a briefing with the pilot's company and they said the pilots know what that clearance means. I will not give that clearance again.
ZLA Controller described an airspace infraction when traffic issued a 'descend via' clearance descended below a crossing altitude on the procedure.