ROCKFORD, Ill. (WTVO) — Forensics took center stage as the murder trial for the man accused of killing McHenry County Sheriff’s Deputy Jacob Keltner moved into its fourth day.

It seemed like the trial could be nearing the end of witnesses the prosecution plans to call, meaning that Brown’s defense will soon be heard from.

A few different FBI agents were heard from on Tuesday. One testified to finding Brown’s DNA on the four firearms that the prosecution claims Brown had in the hotel and his car. They claimed to have found blood on one of the rifles belonging to a man, which she said matched Brown.

Aside from DNA, another agent testified about the shooting the government claims happened inside hotel room 305 that morning. Several U.S. Marshalls testified on Monday to being shot at multiple times while trying to serve Brown an arrest warrant.

The agent said that his team was able to track 11 bullets by documenting holes and imperfections. He claimed that all the bullets appeared to travel from inside room 305 through the door and walls, exiting in the hallway or into room 306 across the hall.

An FBI agent testified on Tuesday that on Jan. 6, 2019, Brown’s computer data showed him searching and watching videos about “cops being ambushed” and “cops being shot.” He said that the data shows those searches continued throughout the day, with searches like “how to avoid surveillance, offensive shooting skills and how to clean a M14 rifle.”

Fast forward to January 12, he claimed that the data showed Brown searching for bullet proof vests for sale. The agent testified that the next day, Brown’s data showed him searching and watching YouTube videos titled “U.S. Marshall shot” and “Moments after U.S. Marshall Deputy was shot and killed while serving a felony warrant.”