Regional Jet 700 ER/LR (CRJ700)
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 2.5
Communication Breakdown
Conflict Ground Conflict; Critical; Ground Incursion Runway
Air Traffic Control Separated Traffic; Air Traffic Control Issued New Clearance
Human Factors
A CRJ700 was on 1 mile final Runway 13 cleared to land when I began my final scan.  It was hazy so I waited until I could see the aircraft to double check the gear position.  I did my final scan of the runway when I saw a BE35 just north of the centerline on Runway 13.  I issued the 'Go Around' instruction to the CRJ700 estimated of 1/4 mile final. I then instructed the CRJ700 to climb to 3000 feet and contact departure.  It is my understanding that the ground controller was under the impression the BE35 was at the South Ramp and they were instead at the East Ramp.
BTR Tower Controller reports a runway incursion requiring him to issue a go-around to a CRJ-700 on short final. The incursion was partly caused by Ground Control issuing a taxi clearance to a BE-35 without being clear on the starting point.