Since finding a set of keys in the Schuylkill River confirmed to belong to Shane Montgomery, police have found no trace of the missing college student in the vicinity.

According to the Philadelphia Inquirer, the Garden State Underwater Recovery Unit found the keys last week, one of the biggest finds in a search that has lasted more than a month. Montgomery, a 21-year-old student at West Chester University (WCU), was last seen outside a pub in Philadelphia early in the morning on Thanksgiving.

With no new developments since finding the keys, Kevin Verbrugghe, Shane's uncle and a spokesperson for the family, said determining what to do next has been "tough." Montgomery was last seen in surveillance tape crossing a footbridge to a parking lot near Kildare's Pub. The keys were found close to the parking lot, the Inquirer reported.

A group of eight divers covered different parts of the river floor while the family braced for the effort to end the agonizing search.

Greg MacTye, the divers unit's captain, told the Inquirer the real challenge in locating Montgomery has been the absence of anyone who might have seen anything. The student apparently left Kildare's without issue and then walked alone. The pub seems to be the last place where he had any human interaction.

"If I can get an eyewitness," MacTye said, "I can usually find them."

According to NBC Los Angeles, the search party plans to investigate Venice Island, a small piece of land on the river where there is a playground and a theater.

Meanwhile, Montgomery's family is offering $65,000 for information that leads to Shane's finding. Anyone looking to provide a tip or learn more about what they can do to help should visit HelpFindShaneMontgomery.com.

"I'm not going to stop until I find Shane," Karen Montgomery, Shane's mother, said on NBC's "Today Show" last week. "I text him everyday to ask him to help me find him."