Five days have passed since a shooter stormed a Brown University classroom, killing two students and wounding nine others, and the gunman remains at large.

Providence Police Chief Oscar Perez told ABC news late Wednesday that officers are continuing to actively collect evidence and canvas the campus.

“It is a very intense investigation, it’s complex,” he said, adding he believes “we will find the individual responsible.”

“…Being a police officer, you have to be patient. You have to be patient, because you’re going to get a break.”

At a news conference earlier Wednesday, Perez said “investigators had recovered DNA evidence from the scene and that they were also seeking a second man, who appears to have crossed paths with the possible gunman in the hours before the attack,” the New York Times reported. The second man is someone who “may have relevant information to the investigation,” Perez said.

The Times reported that a “law enforcement official familiar with the case, who spoke on condition of anonymity because the person was not authorized to speak about the investigation, said that the DNA, as well as fingerprints, came from shell casings at the site of the shooting.”

The person of interest in the shooting apparently cased the neighborhood prior to the attack, and police are asking residents to review their security cameras for any footage they may have obtained, NBC reported.

On Tuesday, Brown University officials confirmed what had already been widely reported in news articles, that the two slain students are Ella Cook and Mukhammad Aziz Umurzokov, the Brown Daily Herald reported, adding:

Cook and Umurzokov were both attending a review session for ECON0110: “Principles of Economics” in Barus and Holley room 166, though Umurzokov was not a student in the class — he had gone to provide his friends with company. 

Shortly after the review session ended, a gunman entered the room and opened fire, killing the two students. An additional nine victims were hospitalized, one of whom remains in critical condition. Five are in critical but stable condition, one is in stable condition and two have been discharged.

Meanwhile, Brown University President Christina Paxson is taking criticism for her response to the shooting, Fox News reported. Asked at a news conference Tuesday why the university did not have video from inside the building, or any idea of a motive, she dodged answering the questions directly.

President Donald Trump on his social media page posted: “Why did Brown University have so few Security Cameras? There can be no excuse for that. In the modern age, it just doesn’t get worse.”

A state official has said the shooting took place inside an “older” building at the edge of campus, WCVB reported.

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