Concerns about a possible serial killer have left Lansing, Michigan, a Big Ten college town, on edge.

Earlier this month, the Lansing Police Department said it was examining whether five recent deaths could be linked to an attacker believed to be targeting people along the Lansing River Trail.

“I definitely think we need to be cautious, but we also need to be rational,” Karen Holt, a criminology professor at Michigan State University, told News Outlet.

Police said five men were attacked along the popular trail during the past year. One victim was found stabbed to death beneath a bridge.

“As someone who studies violence, the first thing that came to mind was the victims, their vulnerability and the method of the violence,” Holt said.

Police said all five victims were homeless.

“If we have a community where people can be attacked in this way, then I don’t necessarily know that we can call it a safe community,” Holt said.

She added that single and serial homicide offenders, as well as other violent criminals, often target people who are especially vulnerable.

Holt said homicide offenders may view homeless victims as people who “lack credibility” and may believe targeting them “decreases the likelihood that they’re going to be caught.”

Edward Joseph Smith, 23, was arrested Sept. 3 in connection with the fatal stabbing of Daniel Lusk, 22.

“I would love to learn more about the relationship between that victim and perpetrator,” Holt said. Police have not disclosed a motive in Lusk’s killing.

Smith has not been accused of any crime or wrongdoing in the four other deaths.

Holt said Lusk’s killing “stands out” from the other suspected cases because he was stabbed, while the four other victims suffered head injuries or possible blunt force trauma.

Police have not announced an arrest in connection with the possible serial killings.

Holt maintains Lansing needs to remain vigilant.

“Don’t walk the trail would be my advice. Maybe walk a different trail.”