As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING THE CLIMB OUT AFTER TAKEOFF FROM MLU. THE PILOTS NOTICED THE OIL PRESSURE ON THE LT ENGINE WAS COMING DOWN. WHEN IT WAS SHOWING NO SIGN THAT IT WAS GOING TO STABILIZE THEY SHUTDOWN THE LT ENGINE WHEN IT GOT IN THE YELLOW PRESSURE RANGE. THEY TURNED AROUND AND LANDING BACK AT HOME BASE (MLU). DURING THE INVESTIGATION OF THE LOSS OF OIL. IT WAS FOUND THAT THE OIL SIGHT GLASS WAS WHERE THE OIL WAS LEAKING FROM.