PROVIDENCE, R.I. (AP) — Police renewed their search Monday for the gunman who killed two Brown University students and wounded nine others, a day after they released a person of interest in the case.

Here’s a look at what to know about the shootings and the manhunt:

Search renewed after person of interest released

Authorities announced the detained man’s release during a news conference late Sunday. That marked a setback in the investigation of Saturday’s attack on the Ivy League school’s campus and added to questions about the shooting and investigation, including an apparent lack of video evidence and whether the focus on the person of interest might have given the killer more time to flee.

In releasing the man police had detained at a Rhode Island hotel, investigators were apparently left without a known suspect. State Attorney General Peter Neronha acknowledged the seriousness of the situation, stating, “We have a murderer out there.”

A busy time on campus

The shooting occurred as students were taking final exams. The gunman opened fire inside a classroom in the engineering building, getting off more than 40 rounds from a 9 mm handgun. Investigators recovered two handguns and two loaded 30-round magazines at the scene.

One of the nine wounded students has been released from the hospital, while seven others remain in critical but stable condition, and one is in critical condition.

New efforts to find the shooter

With the person of interest's release, law enforcement has pledged to intensify their efforts by asking neighborhood residents and businesses for any video surveillance that might assist in identifying the shooter. Authorities mentioned that one reason for the lack of video was due to the engineering building’s limited surveillance coverage.

As investigations continue, the Brown community is mourning the losses, holding events to honor the victims while classes are canceled for the rest of the semester.