"I'm very relieved that it's finally in the court room." Children's advocate... Sylvia Bruni was among those in the court room for the opening day of the widely anticipated Katherine Cardenas trial. The little girl was sexually abused and strangled in september of 2009. Since then, the case has gained much attention. Jose Arredondo is accused of raping and killing baby Katherine. He sat there motionless as the medical examiner discussed the graphic nature of Katherine's injuries. The defense showed disturbing pictures of Katherine bruised and bloodied, which mostly everyone in the courtroom turned away from due to the violent nature of the pictures. The medical examiner even used a doll to show the jury how Katherine was raped, face down on her stomach. Something that caused many in the room to get emotional. "You keep thinking of your own and it's literally incredible that something like this could have been done to a baby." The defense also showed the dirty shirt Katherine was wearing at the time of her death. A federal agent took the stand briefly to say he had retrieved 47 phone conversations during September 5 th- October 1st between Arredondo and his father Miguel who was in prison at the time. One of which Arredondo allegedly confessed to killing the 2 year old say "Yo Fui".."I did it" in Spanish. It was time for Arredondo's mother to take the stand. She answered a few questions about the morning she found out about the death of the two year old girl, saying she knew her son was going over to the house where Katheryn lived with some friends and how he was acting weird the days after Katherine's death. She remembered asking him what was wrong and Arredondo saying he was high on drugs and thought he killed the little two year old. According to his mother, he went to sleep on a sofa in Katheryn's house and woke up with her in his arms. "I can't imagine anyone sitting there and viewing and listening and not being terribly affected by it." Arredondo's mother also recalled how she sent him to his grandmother's house in Nuevo Laredo instead of turning himself in. It wasn't until a phone conversation was played where she told her ex-husband their son Jose killed Katheryn that she broke down in tears. She couldn't contain her emotions and neither could the defendant who was accused of the murder when he was just 16. "That baby is going to God willing receive justice because I've never seen anything this horrible being done to a baby girl."