On Tuesday, dozens gathered at the scene of the crash to mourn the loss of the teenager.
"I wish I could bring her back. I wish somehow she could come back because this is pain. We're all suffering. We don't need this," said Christy Rivera.
"To all this to happen and not even say goodbye or I love you to her again it just hurts. I hope she's looking down at me right now and knows that I really love her and I wish she was here with us today," added Rivera.
Around 8:30 Monday night, Waterbury police were called to the corner of Thomaston Avenue and Driggs Street for a car crash.
Upon arrival, police found the car in flames. Community members helped put out the fire where Santiago was found in the passenger seat.
Police said she was shot in the head several times and once in the hand.
Police arrested Dominique Pittman, 27, of Waterbury and charged him with murder and weapons violations. He is being held on $1 million bond.
Police said Pittman was having a relationship with Santiago.