First, judges don’t investigate crimes; law enforcement does.
Second, there WAS an investigation that culminated in 2000 mules film. Investigative journalism is still a form of investigation. The evidence from the film, while popular among stolen election claimers, was still not conclusive nor substantial enough to press charges nor open an actual case.
The so-called evidence was that there were multiple people who worked around or near voting areas, including government officials, police offers, and volunteers passed by the same public thoroughway multiple times a day, which is where most voting locations are. Public libraries, police stations, and other government buildings.
There was nothing abnormal about that.
The same people from 1000 mules could have easily tracked that cellphone data on any other day, before or after the elections concluded, and gotten mostly the same results.