Police have issued an arrest warrant for the suspect in the Brown University mass shooting that killed two students and injured nine others, sources told CBS News. The suspect's identity has not been made public. Authorities are searching for the possible rental car linked to the suspect. They are also investigating a possible connection to the killing of an MIT professor two days later. Nuno F Gomes Loureiro, a 47-year-old MIT nuclear science professor, was fatally shot at his home in Brookline, Massachusetts. Police found a rental car matching the same description at both crime scenes. On Wednesday, police released a photo of a person believed to be close to the suspect, and released footage of a man wearing a black mask walking around the Brown University campus, possibly scouting before the attack. Providence Police Chief Oscar Perez said, "We don't know where the person is or who he is," and warned the suspect "could be anywhere." The FBI has offered a $50,000 reward for information leading to the suspect's arrest and conviction. The shooting took place in Brown's Barus & Holley engineering building during final exams. The two victims were Ella Cook, a sophomore from Alabama, and Mukhammad Aziz Umurzokov, a freshman from Uzbekistan.