Sarah Papenheim, an American college student, was fatally stabbed earlier this week. The 21-year-old was studying in the Netherlands at Erasmus University. Dutch police answered a call to her apartment, where an argument and screams were heard. There, they found her body. Authorities consider her roommate the prime suspect in the case. They arrested the 23-year-old Dutch man at a train station. Meanwhile, flowers and candles were left outside Papenheim's apartment building.