Jobs that offer TS/SCI?

I’ve been wanting to be a background investigator for so long, but I am discouraged as many of the big companies like Perspecta, CACI, and Constellis are only hiring already cleared people. I want to work in investigations/research. Does anyone know of other jobs that are similar to BI in terms of the daily activities of the job itself? I’ve been looking at intelligence analysts and research analysts and I’ve been running into the same problem with them wanting you to already have clearance. If anyone knows of any jobs that are similar and are willing to hire civilians and sponsor them for clearance, please let me know!