Recently released surveillance footage in the search for the suspect involved in the Brown University shooting reveals a masked individual whose demeanor shifts from composed to uneasy and erratic. This behavior, according to a body language expert, is indicative of “anomalies” typically observed in individuals with harmful intentions.

“From a behavioral standpoint, actions such as looking around, pacing, and placing hands behind the back are often linked to loitering behaviors and suggest someone is actively surveilling their surroundings instead of merely passing through,” explained Susan Constantine, a certified expert in threat-assessment behavior. “These actions align with behavioral anomalies seen in individuals with malevolent intentions.”

In a conversation with Fox News Digital, Constantine noted that in the early segments of the video, recorded prior to the incident, the suspect appears “focused on a destination.”

“He’s engaging in scouting and rehearsal,” Constantine observed about these initial recordings. “He is mapping out paths, potentially timing routes, and noting the positions of CCTV cameras.”

The footage, consisting of multiple stills from surveillance near Brown University, captures the individual both before and after the shooting on Saturday. These specific moments, highlighted by Constantine, show key signs that could aid in identifying the person of interest.

However, it wasn’t long before the suspect’s behavior raised suspicions, particularly through “a really important marker” identified in his distinctive walking style, Constantine added.

“When crossing the street in the middle of the block, the subject’s pace quickens, and he seems to be in a hurry. His gait becomes hurried, and a more waddling gait can be seen. He has his right hand in his pocket. It is not possible to determine if he has a weapon or not, but concealing the hand and object within it inside a pocket is a form of concealment. The subject’s right lower leg also bows outward as he walks, resulting in an abnormal gait.”

WATCH: Surveillance videos show person of interest in Brown University shooting

The Brown University shooting person of interest running in a still frame taken from video. Constantine said this image makes it appear as though the person of interest is not as stocky as initially viewed. (FBI Boston)

Police in Providence, Rhode Island, have released multiple video clips and other surveillance images in the hope that members of the public can help identify the person of interest, who remains at large more than 72 hours after a mass shooting in a lecture hall Saturday.

FBI Boston released a timeline of surveillance camera footage that captures a person of interest in the Brown University shooting. (FBI Boston via X)

“Taken as a whole, the characteristics of a heavy or stocky build, behavioral changes, hyper awareness of surroundings, pacing movements, bulky clothing, facial and hand concealment, and a hurried pace with a waddle as he walks and his right lower leg bowing out as he walks are characteristics that could be used to track this person in the future,” Constantine said.

FBI Boston released a timeline of surveillance camera footage that captures a person of interest in the Brown University shooting. (FBI Boston via X)

In particular, she said the videos show his right leg bowing inward while his toe points outward as he walks. And he could be right-handed, she said, based on how he walks with one hand in his pocket and the other swinging freely.

FBI Boston released a timeline of surveillance camera footage that captures a person of interest in the Brown University shooting. (FBI Boston via X)

“These are behavior traits that cannot be controlled,” she explained. “That’s what’s causing him to waddle. Could be a knee injury.”

The attack left two students dead, identified as Ella Cook of Alabama and Mukhammad Aziz Umurzokov of Virginia, and nine injured.

FBI Boston released a timeline of surveillance camera footage that captures a person of interest in the Brown University shooting. (FBI Boston via X)

Authorities said during a Monday news briefing that they recovered 9mm casings at the scene.

Police released additional surveillance clips Tuesday afternoon, one of which showed the purported person of interest walking right by officers as they responded moments after the shooting. The additional footage, in higher resolution, shows the person is not as stocky as initially expected, Constantine said, especially during a portion where he is seen running along a picket fence.

“He is concealing something under his jacket,” she said. “He is not as stocky as first viewed.”

The gunman remains at large.

Anyone with information is asked to call Providence police at 401-272-3121 or submit tips to the FBI online.