Law enforcement often deploy networks of fake cell phone towers that are capable of tracking the cell phones they connect with. You can read more about fake cell phone towers here.
Computer vision on security camera footage.
The company Clearview AI sells a tool to law enforcement, allowing them to search for matching faces from billions of images scraped off of social media. If you or anybody else has posted a picture of your face on the Internet, you should assume that Clearview and similar companies already have a copy, and that law enforcement can find your Internet presence based on photos of you taken from security cameras.
There are many other companies that sell or offer the ability to build computer vision models capable of facial recognition, such as Matroid.
Requesting data from private companies that track your location.
Law enforcement often request information from major social media, mapping, or ridesharing companies. They may make these requests with or without a warrant from a judge. It is common for companies to notify a user when law enforcement is requesting that user's data, but companies are often barred by law from contacting users.