That is horrible. And unforgivable. I would consider moving somewhere else after paying off her debt. I think it is too dangerous not to. If you trust the police enough, you could inform them without pressing charges. That way they chould not know that you have told the police about them. If I were you. I would try to cut all my ties to this place. If they have come for you once they could do it again. I think you and your family deserves to live without fear.
Nobody said you HAD to forgive your mother!
Oh, wait - strike that - they probably did. Oh, aye, the uninitiated and ignorant are very fond of lecturing about 'granting forgiveness' as if they arrogantly believe they (and we) are each all Jesus Christ reincarnate himself or something. However, Forgiveness is not an act, but a result. Of the grieving process, repeat, PROCESS. It controls you, not the other way around. (You can go relatively smoothly with it or you can turn it into a ride from hell by struggling and resisting every step of the way, but, going, you are, whether you like it or not so - may as well go quietly, eh.) Hence why these bleaters, once finding themselves in the 'called to forgive' position, find it much harder to practise than to preach. *Much*. Especially in your type of case, having to do the hardest thing any living human ever has to deal with in their lifetime because - your grandma and grandpa's death is the closest you'll ever get to dying whilst still alive *and* you've then got a major (umpteenth) betrayal by the person who was supposed to be your mother and Number 1 Protector, added on top (woah!).
Said process is: Shock, Anger, Denial (or Denial, Anger), Plea Bargaining, Depression, (the lesser-known Formulating Solutions), Acceptance (in order or as a position-variable set of 'run-up attempts') = Forgiveness. And it's a bi-part affair, meaning, forgiveness of the transgressor simultaneous with forgiveness of yourself and the part you played (even if that was nothing more than how, as an adult, you let how it affected you effect sometimes (or just hadn't known to watch out for), in ways that weren't self-productive, i.e. being only human, not Jesus...an easy-peasy forgiveness portion, therefore).
You are 100% justified at feeling angry and betrayed, so much so you daren't open the Pandora's Box even a fraction of a millimetre in case it's less of an escape than a nuclear explosion (it wouldn't be; our imaginations always over-estimate the negative). Fully qualified. And as Anger is the entry springboard to that very necessary multi-part process (albeit, Shock is more merely the incoming memo getting read and digested). If you fail to allow and express it, it's like wondering with frustration, why the elevator hasn't arrived when you never pressed the Call button. (Say it with me - "duuuh".) And yet, there you are, sounding like Spock or a Police arrest form ("...and then the suspect did X, after which he Y-ed, and when questioned said,...").
For the sake of that little boy, you need to start releasing that warranted, therefore healthy, anger (...well, healthy IF you release it; otherwise the chemicals will 'go off' and become trapped toxins). So that you have all the brain cylindry you possess at your disposal for being THE best dad you could ever be and clearly want to be (pointed mention of fatherly hands-on-ness noted, in other words). Include expletives if you so wish; all I ask (demand) is that you asterisk as well as try to keep it to within reason in terms of viewer impact or any lurking minors who took a wrong turn. But if you want to say (not necessarily because you mean it, just because it's the only available vomitus for the harmful virus to attach to in order to get expelled from the body (mind)), 'My so-called mother was nothing but a [insert cuss-words and exclamation marks galore]' and 'I miss granny and grandad so [beeping] much!!!!!', then, go for it with my blessing.
Put it this way.... In this world, for every physical manifestation/environmental tangible there is a psychological equivalent. So - QUESTION: if you needed to do a giant poo but held it in and held it in and held it in...day after day after day - what do you imagine would befall you as a result? Not a rhetorical question - RSvP.
From a practical perspective, you do need to report this to the Police immediately and *ignore* that ridiculous, self-placed blockade about 'all that'll probably happen is he'll get done for assault'. For starters, you're not a front-line, member-expert of the British judiciary (so that's just your imagination again, not reality) and, secondly, I'd say this piece of work sounds very much like the type plus level of 'professionalism' that'd have long been a Police target already - wouldn't you? I mean - one customer, THREE THOUSAND POUND BILL? What - you think she was his sole customer?! And that he/they let her remain 'on tick' for some incredibly lengthy period, do you? Come ON - do the Maths! So that tells you his level, right? You need to explain to the Police your situation and fear of reprisals at his or any associate's hands to SEE what can be done to prevent it. (There's a woman and baby involved too, remember? Even ASIDE from their self-made choice to be real-live heroes - do you really think none of the personnel at your local or central station are dads, husbands, brothers, etc., or despise serious drug-dealers with a passion?) *However*, as this creature's crime toward you was indeed 'just' physical assault and intimidation, the choice about whether to prosecute after you've had that consultation chat is entirely yours. Unless he's been under surveillance and your report is just the excuse/catalyst they needed to send the ugger down, and it were likely during any raid that enough of his posse were with him to ensure no associates of any concern remained free to roam? Again, these questions are the sort that would arise and get addressed.
Baby Steps. Just ask for a chat with the station Sergeant. All you have to do to be a better parent than your mother is [wait for it] TRY HARD ENOUGH aka give it a proper go. You're her biological Automatic Upgrade. So act like it. However, FYI (in case it removes some of your paralysis) your mother didn't ever reject you. It's not possible because that's an action that requires freewill choice-making as well as deep and expansive knowledge of the person concerned (you can't reject something you aren't intimately familiar with or it's just 'a failure to accept/attempt/start' - think about it)...something your mother, following the very first hit, ceased to possess. (If you've done your research on Heroin addiction you'll know that it's like casino gambling: only the very first hit is amazing and thereby first-time addictive; by the very nature of Heroin and how it effects, all subsequent hits are a complete let-down. "But - oh!...that first time was amazing so surely if I try again, it'll be like it was?". Answer: nope! It's an abusive type of chemical lover, all mouth during the Honeymoon Period but no trousers thereafter....Walk Away the minute it ceases to live up to initial promise(s) (in that context, as a sign of or bid for *strength*, not weakness), taking your experience (the first-stab winnings) with you.)
Failure is not 'trying but not succeeding first-time'. It's never trying the once to, this case, WALK AWAY.)
That's what you going to the Police, MERELY TO FIND OUT WHERE YOU STAND is all about. They walk in, you walk away (from this thug, this world, and your past world association). Not making mum's mistake (failure to employ the reserve iron-will determination tank).
...Sorry, I should say 'blood mum' (whom, BTW, neglected you *once*, after which, she had no say in the matter about it becoming an ongoing, never-ending affair). Because, let's be real here in considering the truth in the statement, that the word Mother has to be a verb before it can qualify as a noun/status label/fact. I could walk outside into the street and up to a lamppost and call *that* Mum, couldn't I? Doesn't make it so, does it. So let's not minimize your agony: "Granny" was your mother and "Grandpa" your father. So let's edit:
In September 2015 you lost your mum, closely followed by your dad. If that doesn't deserve, nay, DEMAND a damn good free-license venting on a public forum, I don't know *what* does! Do you?
It's puke time. Because that, actually, is what is stood in your way on your current path as is then making you veer towards making the wrong and foolish decision of not acting urgently to protect yourself, your wife and your mini-me using the no. 1, free tools at your environmental disposal, and instead DO NOTHING but procrastinate, followed by asking a 'roomful' of strangers, rather than Police personnel, to make what is your decision AND HANDS-ON STATUS-RIGHTFUL PRIVILEGE *for* you. Well, all anyone can supply is 50% whilst relying on you to add your own 50% (because only *you* possess the legs and mouth that are going to be entering that station as turn it into a reality).
PS: Legally-speaking, you have 3 months in which to report it or even to discuss making it a formal charge. Morally and dutifully speaking, you have minus - what - 2 weeks? But well done for having gone ahead with seeking help on here as your first Baby Step.
At least you've got yourself moving, and that's the main thing. In fact, the only thing (no start = no middle or ending). You're at Formulating Solutions, in case you hadn't realised? One more step or set of little steps and you're there! 'Little' being relative to the decades of heartache you've already endured. And anything's got to be easier than that, right?
Hope that helps even if you don't RSvP.