Five days after a deadly shooting at Brown University that killed two people and injured nine, authorities have not identified a suspect, keeping the campus community on edge.

Investigators released new images of a person they want to question, believed to be near the primary person of interest seen on surveillance footage before the attack.

Police say the individual appeared to be casing the area and are seeking public tips and home security video to track his movements.

Officials insist the investigation is progressing, despite criticism over campus security coverage, and say there is no ongoing specific threat, the BBC has reported.

Law enforcement has increased its presence around Brown and nearby neighborhoods as a precaution.