A.     Any student who commits an expellable offense and is subsequently committed to a juvenile detention center, the Connecticut Juvenile Training School or any other residential placement for such offense may be expelled by the Board in accordance with the provisions of this section. The period of expulsion shall run concurrently with the period of commitment to a juvenile detention center, the Connecticut Juvenile Training School or any other residential placement.

B.     If a student who committed an expellable offense seeks to return to a school district after having been in a juvenile detention center, the Connecticut Juvenile Training School or any other residential placement and such student has not been expelled by the board of education for such offense under subdivision (A) of this subsection, the Board shall allow such student to return and may not expel the student for additional time for such offense.