Prosecutor claims Kristin Smart was killed by fellow student Paul Flores during an attempted rape in 1996 and his father helped hide the body
Paul Flores will be charged with first-degree murder and his father, Ruben Flores, will be charged with accessory after murder
The son and father were arrested Tuesday after years of investigations and searches that recently led to evidence connected to Kristin Smart's killing
Smart, 19, was last seen May 25, 1996, while returning to her dorm at California Polytechnic State University in San Luis Obispo after an off-campus party
She was inebriated at the time and Flores, a fellow freshman at the school, had offered to walk her home