Step 1: Materials
PVC glue is also recommended unless you don't mind your police baton falling apart all the time.
Your also going to need a saw to cut the pieces to the right lengths.
Step 2: Connect the Pieces
Piece 1: from the length from your fist to your elbow
Piece 2: an inch wider than the width of your hand
Piece 3: 4 inches long
Then connect the pieces as shown below.
(Glue them together if you can)
Step 3: Other Stuff
DISCLAIMER: DO NOT ACTUALLY BEAT PEOPLE UP WITH THESE. POLICE BATONS CAN BE DANGEROUS AND IF SOMEONE GETS HURT BY ONE OF THESE, IT IS NOT MY FAULT.