The 43-year-old former senior Continuity IRA figure was shot a number of times as he sat in an office in the Peter Pan complex on the Springfield Road at 4.45pm last Friday afternoon.He was hit in the upper body and was pronounced dead at the scene.Exactly a week on, officers from the PSNI Serious Crime Branch returned to a number of scenes linked to the murder to ask people for information which may help with their inquiries.An old style red BMW coupe, registration number OEZ 9177, which was found partially burned out in the Beechmount Grove area is now being treated as a key strand in the murder investigation.Police want to hear from anyone who saw it in between 3.45pm and 5.15pm in these areas: The Springfield Road and Springfield Avenue; The Peter Pan complex; Beechmount Crescent, Mica Street and Mica Drive; Beechmount Grove.The officer leading the investigation, Detective Superintendent Jonathan Roberts, said: "The movements of the red BMW car are an important strand in our investigation."We need to know where it was in the hours before Mr Crossan was brutally murdered."We are also keen to speak to anyone who saw any person or persons coming out of an alleyway which runs between Beechmount Grove and the Mica Street/Mica Drive junction between 3.45pm and 5.15pm and whether they saw any person or persons get into a vehicle during this time."Detective Superintendent Roberts went on to describe the appearance of the vehicle.He said: "The car was slightly unusual in that the shading of the red on the front offside quarter panel, bonnet and bumper appears to be slightly lighter than the rest of the car."Information can be passed to the PSNI by calling the murder incident room on 028 9025 9542.