警察昨晚带走他了

这已经是他第5次动手了，我曾经警告过他，再动粗我就会报警，没有用的。。。记得有一篇研究报道写的是男人打老婆这种事发生过3次后他就会成"瘾",其实在第一次过后我就应该狠下心来和他离婚,也不至于到今天这种地步.
昨晚我抱着小孩子他还一直的推我,把我们推倒在地上几次,小孩子哭得太厉害,我要一直都抱着他, 打了我的脸,还举起小吸尘器威胁要打死我,要我给他下跪...后来我只好和他说软化,把他骗到离我有一定距离的地方,溜了个空抱着小孩子跑到邻居家报的警...
直到警察来了...我看到他给警察写的about what happend, 取轻避重不说还捏曲事实,基本上把自己说的没什末错,只是"碰了我肩膀 to stopped me from running too fast, since i was holding the child" blah blah ... 我身上没有什末伤, 这给他编造理由创造了条件. the police told me that they will release him this morning at 8, then he is allowed to come back home to get his belongings, but not without accompnay with a police.
我不能也从来没有想过要去"毁了" 他,但事情到今天这个地步我只能是尽最大努力给我自己和孩子一个公平和安全保障.i have to protect my own rights.
今天是sunday, the offices are closed, i am sitting here in front of the computer, wishing all of these did not happen to my family,but i also know that i will have to face the reality, as i said, i have to protect my own rights and get divorce from him, could anyone please advice what my next steps are?
P.S. i know for sure that he will flight with me for the custody of our son who is now 2 years old. i will do anything to make sure that the custody is mine, please please advice. this is from canada

thank you for your time.