The mother of an 18-year old man who currently sits behind bars is speaking out. He has been accused in the shooting death of a 16-year old Aransas Pass girl, Jenna Hernandez.

Police released the arrest affidavit in the case Thursday. It outlines the events leading up to the girl's death.

It has been one week since the teen's body was found on Stedman Island in Aransas Pass. Police arrested Lawrence Mireles, a former boyfriend of the Hernandez. However, the suspect's mother said her son could never have committed the crime he's been accused of.

"He's so calm. He says, 'Don't worry about it, mom. I didn't do it. There's no way they can say I did this,'" said Kayecee Collins, Mireles' mom. "I just want everyone to know I can't see him doing this."

The family, along with their lawyer, believe police have the wrong man, claming he was at a graduation party in Rockport the night Hernandez was murdered. However, according to the affidavit, a witness said Mireles confessed to him just one day before the teen's body was found. That witness reported that Mireles told him he was drunk and on Xanax when he shot her.

The affidavit states that Hernandez' mother, Jennifer Lanier, reported her daughter had been texting with Mireles in the early-morning hours of June 26. She told her sister she would be back before leaving the home at around 1 a.m. She was supposed to go with Mireles, and never returned.

The suspect's family is challenging the report.

"It's hard, because my son may be in jail the rest of his life for something he didn't do, because the town is just saying it's him," Collins said. "It's such a small town, everyone is believing it."

"The officers and investigators assigned in this case are working very hard, even before the body was discovered, and they will continue to put forward that same effort to work off the facts established in this case," Aransas Pass Police Chief Eric Blanchard said.

The affidavit also states that phone records indicated Mireles had been chatting with Hernandez, and with the use of cell phone towers, police were able to track his location from Rockport to Aransas Pass.

Mireles' family simply believe he's been convicted before he's even gone to trial. Aransas Pass Police Chief Eric Blanchard said more arrests are possible.

The Aransas Pass Police Department is working to transfer Mireles to the Nueces County jail. It turns out that where the victim was found on Stedman Island falls under Nueces County.