I've used them for several years now (about 4 or 5) to screen candidates before hiring - they have always been excellent in their service delivery! No complaints here at all as far back that we can remember!! Highly recommended with confidence.
They do not charge additional fees if you need more than just an initial run through when interviewing new employees/candidates who must go thru extensive pre-employment drug screens & other types required by state laws etc.. The process was very easy to follow through from start-to finish! I could not have been happier with how everything went down as far along in our hiring journey goes for my organization; we received great feedback when it came time that they were done working at this point which made me feel completely comfortable using them again should another position open up within 6 months or so after their work completed (which has already happened).