Large amounts of her blood and Josephson's cell phone were found inside his car, according to investigators. Authorities also found a container of liquid bleach, window cleaner and sanitizing wipes.
Josephson was a senior at the University of South Carolina with hopes of continuing her education at Philadelphia's Drexel University, according to her family.
Officials suspect Josephson accidentally climbed into Rowland's car thinking it was the Uber she had been waiting for in the 5 Points section of Columbia.
"It is with the heaviest of hearts that I write these words this morning. Our prayers are with the family and friends of Samantha Josephson following the devastating news of her death," USC president Harris Pastides said in a statement to students.