New details in the case of missing college student Lauren Spierer suggest she may have gotten into an argument with a group of students shortly before she vanished last weekend. According to published reports, new surveillance video shows Spierer, a sophomore at the University of Indiana, returning to her apartment building with a male friend at around 2:30 a.m. Saturday. Several media outlets have identified the man as fellow Indiana student Corey Rossman, 21, of Mass. Police have confirmed the pair left the building about 10 minutes later. Further reports say she is seen on the video while an argument takes place between Rossman and several other students. Police and Rossman's attorney say Spierer visited Rossman's apartment down the street, and was last seen after rounding a corner on her way back to her residence at about 4:30 a.m. Her shoes and cell phone were found in the bar she was at earlier in the evening, and her keys were found close to her apartment. Police dive teams searched nearby Lake Monroe yesterday with boats and sonar equipment, and are expected to continue those efforts later today. Spierer's family is offering a $100,000 reward for any information leading to their daughter's safe return.Ind. police step up search for missing student from Edgemont