As usual when I get enough dream material to read through, "a little to add" becomes a lot. And at least one more short round of questions can take us even farther.
The major thrust of Mrs. Sandman's interpretation is quite valuable, that you are "re-viewing" your life (thru the videotaping venture at your schooling) and noticing how many of your earlier learnings/experiences have (already) been eliminated. Your age of 29 is very significant, because you are on the threshold of graduating from experimental adulthood (your 20s) into "committed adulthood" and that means you need to figure out what is worth your ongoing commitment, by evaluating the results of your experiments with adult activities up to now. (When I was 29 I lost my job as a full-time professor of German and Humanities, lost my girlfriend, and got a chance to study myself psychologically and find out if I might prefer being a psychotherapist to being a professor of external arts & letters, as productions of human nature--So I went back to grad school in psychology, and it has turned out that I did both for the rest of my work-career. People who aren't married are likely to start thinking about marriage @ 29, and if they're married they might get divorced in order to commit more to their career and/or a different sort of partnerhip.) Czech genius Franz Kafka wrote The Trial @ 29, about a bank employee that was accused of a crime (in the attic of his dreams) of an unknown sort--because he didn't know what he was NOT yet doing with his life. Your dream places the crime(s) in your immediate past, yet situates them in your schooling: So perhaps your education has taken you in a direction that's not quite right for your soul's progress in this lifetime.
The timing of the killing in your dream doesn't appear to be pointing towards future psychological work you need to do on yourself, of "killing off old parts" but rather towards parts of yourself that you have LOST (perhaps that were pruned away by your more recent experiences as a young lawyer).
That brings up the mother of one of your models. Did it seem like that model was her son, or daughter? or was that just too vague for any sense at all? Did she seem like anyone you could compare her to? If you picture the old lady in your mind's eye now, how do you feel? (warm & trusting, repulsed, horrified, angry at her, or at her killer(s), etc?)
Now that I've reread your answers to my questions, I associate your explicit dream-ego statement "I don't want to be here and don't want to do this" most immediately to your DishWashingJob. That might more distantly refer to doubting whether you want to be a lawyer (at least the kind of lawyer you were), but it's more immediately obvious that you don't want to be a dishwasher who's realizing ("re-viewing") the extent of your losses of aspects of yourself that you developed through schooling. To explore if both are true, I ask this: Who's had the most influence on your choice and direction of career? What aspects of your prior work as a lawyer have awakened passionate feelings and/or the greatest satisfaction in your experience?
Your reaction to your own dream-realization is to leave the school scene where the models are being killed: Models are artificially posed versions of yourself--pictures you (or the other people on your team) have invented to make a movie about. So your dream-directer might be hinting that this is an artificial version of your life story--what you've imagined, or even what other people in your family&friends have imagined FOR you. THIS has been slaughtered by the harsh realities of the Malaysian economy (or more individual dynamics) at present.
So, as Mrs. Sandman has also written, you have the opportunity to revise the dream-movie of your life. Which you set out to begin by returning to elementary school and resuming your brotherly-warmth with other boys. The consequence of this exploratory choice is to glimpse the number 4: Where 4 is the symbol of the wholeness of your human nature--body, mind, emotions and spirit. It's not a state where we can dwell, but a signpost that inspires us to seek whatever we need at this moment to fill in what is missing. Like the light of divine inspiration towards which we instinctively move when we feel it.
So was there any sort of "award" or triumph that you experienced in your early schooling that you DID receive but DIDN'T deserve? Or that you DID deserve but (an)other boy(s) didn't like? Has there been any tension in your life between your own special abilities or unique passions/inspiration and the comradeship you want to feel with other males?
There might be some clues that point towards the way forward in your present unemployment-trap to be found in the personality of the old lady who was the first to be killed in the second killing, and in the elementary&lawschool award that your dream-ego feels you don't deserve but your real-life-association connects with another student's negativity. This reversal of real life in your dream needs careful examination.
I hope you don't mind if exploring these aspects turns up more surprising insight than you expected.
The removal of dampening forces from the benzos and marijuana allows your passions to emerge and be counted.