(NewsNation) — A number of businesses were served with warrants related to the investigation into the stabbing deaths of four University of Idaho students.

This information comes from more than 700 pages of redacted warrants the courts posted late Friday. The court also ruled a number of warrants related to the probe were to remain sealed.

According to the court documents, the businesses that were served warrants include Verizon Wireless, Washington State University, DoorDash, Extreme Networks, Google, Inland Cellular, KA-BAR Knives, Match Group (Tinder), Meta, PayPal/Venmo, Reddit, Snap Inc., T-Mobile, Umpqua Bank, UPS, Walmart, Yahoo and Yik Yak.

Details from other warrants that were previously unsealed show that police in Pennsylvania seized items including clothing, medical gloves, and a cheek swab for DNA collection. They also revealed that suspect Bryan Kohberger was being surveilled while in the state and was tracked using his cell phone.

Courts also previously unsealed a warrant for Kohberger’s apartment, where items seized included a computer tower and portions of a pillow.

Kohberger, a former Ph.D. student at Washington State University, is charged in the killings of 21-year-old Kaylee Goncalves; Madison Mogen, 21; Xana Kernodle, 20; and 20-year-old Ethan Chapin.

The girls were roommates, while Chapin and Mogen were dating. All four were found dead in a Moscow, Idaho rental home near the University of Idaho campus.

Records show law enforcement also requested social media and bank records related to the victims.