What Other Avenues Are There For Proving Constructive Notice In A Negligence Case Against A School?

Location: New York
Context: I’m looking to potentially sue a school for negligence that resulted in 4 months of sexual abuse by another student while on a special education bus back in 2017-2018. Both students were special education students and had BIP/IEPs, victim (me) was a highly vulnerable individual at the time (In age difference, weight, height, social isolation, family issues, etc. I check a lot of the boxes for factors that are associated with the victims). The abuser was much larger and a year older than me. It was on one of those short type A Chevy busses. There was no seating chart or anything of the sort. There was a bus monitor and driver but the monitor just sat up front. I had just gone into sixth grade.
There’s a lot more information but I don’t want to make my post too long.

The main question I have is: How can I prove or at least make a very strong argument for the school districts neglect and specifically the constructive notice without the other students records? I know he had behavioral issues but the exact nature of them and whether they are documented by the school is what I can’t figure out without a lawyer.

I know there are quite a few ways to attack this problem but I’m really looking for the nail in the coffin that will really grab a lawyers attention and convince them this case is worth taking. The ones I’ve talked to have basically said: The case would take a long time, there’s no guarantee of winning, and we usually take them on contingency so it’s not worth it.

To me it sounds like a lawyer is unwilling to take the case unless there was actual notice or very strong constructive notice so I’m trying to do my research and create the best arguments for constructive notice as I can without having his records.

Additional information: I’ve already done foil requests for my records, all of the transportation and school policies and job description stuff from that time.

My question again just to be clear: How can I prove or make a very strong argument of constructive notice without the abusers records?