(Reuters) – The gunman who killed two Brown University students remained at large on Wednesday, and there was no indication that authorities have grown closer to identifying the suspect four days after he opened fire inside a classroom and escaped into the surrounding streets in Providence, Rhode Island.
It is rare but not unprecedented for the perpetrator of a high-profile attack to evade capture for multiple days. But the lack of any identification has left people in the area on edge, with some staying behind locked doors and keeping their kids home from school.
"This is outside of the norm," said Felipe Rodriguez, a former New York Police detective who now teaches at the City University of New York's John Jay College of Criminal Justice. "Mass shooters, by large, are usually killed at the scene or quickly captured."
Investigators have released security camera images of a masked man they believe to be the suspect, based on witness accounts from survivors, but admit they still do not know who he is or what his motive may have been.
"He could be anywhere," Providence Police Chief Oscar Perez said of the killer at a press conference on Wednesday. "We still don't know who the person is or where he is."
Perez called the manhunt "probably the most intense investigation that we have in this nation."
Providence Mayor Brett Smiley told the same press conference he shared the feelings of the city's residents and Brown students who were "restless and eager" for an arrest.
At least eight other people were wounded in the attack. Six of them remained hospitalized.
On Wednesday, police published grainy photos of another unidentified man who they said was in the vicinity of the suspected shooter and have asked the public to help identify him. The images showed a man wearing a jacket over a hooded sweatshirt, his face visible, walking along a street.
"This is a person we would like to speak with," Perez said, describing him as someone "who may have information relevant to the investigation."
Early on Sunday, a day after the shooting, investigators appeared to have broken the case open when they announced a person was in custody. But authorities released the unnamed man in his 20s that evening after evidence showed he was not involved.
Officials said on Tuesday the investigation has been hampered by a lack of security cameras in the building and in the nearby area.
Investigators have released video clips, mostly taken from residential doorbell cameras, showing the possible shooter walking in a neighbourhood near campus both before and immediately after the attack. In one video, the person can be seen walking away from the building right after the shooting as police cars with flashing lights arrive on the scene.
While the man in the video is masked, officials hope someone might recognize his body, gait, movements or posture.
Perez again called on people who live nearby to check their security cameras for any possible sightings of the suspect.
There are some other cases in which attackers have escaped, at least temporarily. The brothers who bombed the Boston Marathon in 2013 hid for four days in the Boston area and then killed a police officer when trying to flee. The older brother died after a gunfight with police that ended when his younger brother ran him over with a stolen car.
Luigi Mangione, the man accused of assassinating a healthcare executive last year in Manhattan, eluded authorities for five days. Mangione was captured in Altoona, Pennsylvania, after he was spotted eating at a McDonald's by a customer and an employee who believed he resembled the gunman.
More recently in September, conservative activist Charlie Kirk’s suspected shooter was taken into custody after a 33-hour manhunt. Suspect Tyler Robinson was captured after a relative and a family friend alerted the local sheriff's office that he had made comments suggesting he had committed the murder, the Utah governor said at the time.