(ABC News) -- In a chilling 911 call, Texas teen Jake Evans spent 20 minutes calmly recounting how he shot and killed his mother and sister, calling himself "evil."
"It's weird," an even-voiced Evans told the 911 dispatcher. "I wasn't even really angry with them. It just kind of happened. I've been kind of planning on killing for a while now."
Evans, 17, of Parker County, Texas, was arrested after he called police early Thursday morning to report he had killed his mother Jami Evans, 48, and his 15-year-old sister Mallory Evans.
"I just thought it would be quick, you know? I didn't want them to feel any pain," he said. "That's why I used a gun, but it was like everything went wrong."
He has been charged with capital murder, according to court documents, and is being held without bond.
Evans did not give a specific reason for the killings, but said that he didn't "really like people's attitudes" and said people were "verbally rude to each other."
"I guess this is really selfish to say, but to me, I felt like they were just suffocating me in a way," he said calmly. "I don't know.Obviously, you know, I'm pretty, I guess, evil."
He told the operator that he told his sister that his mother needed to see her. When his sister came out of her room, Evan said he shot her. She rolled down the stairs and he shot her again, he said.
"I'll never forget this. My sister, she came down the stairs and she was screaming and I was telling her that I'm sorry but to just hold still--that, you know, I was just going to make it go away," he said. "But she just kept on freaking out, but finaly she she fell down, and I got her in the head about, probably, three times."
He said he then shot his mom three or four times with a .22 revolver. The gun belonged to a family member, according to ABC News' Dallas-Forth Worth affilate WFAA.
"Just to let you know, I hate the feeling of killing someone. I'm going to be messed up," he told the operator. "I'm really worried about nightmares and stuff like that. Are there any type of medications for that and stuff?"
"I don't mean to sound like a wimp or anything, but this is, wow, I've never, like, done anything violent in my whole life," he added.
When police arrived at the home, Evans was standing outside with his hands in the air and was arrested without incident, according to police. Authorities believe Evans' father was out of town on a business trip when the shootings occurred.
Jami Evans was a teacher and an assistant principal at schools in the Aledo Independent School District from 1989 to 2004.
"Aledo ISD is deeply saddened to learn of the death of a former employee and a former student," the school district said in a statement. "Her dedication to her students and her love of learning was an inspiration to all who knew her."
"We also mourn the death of Mallory Evans, a former elementary and intermediate school student," the statement said. "She was a sweet child that will be missed by her friends and school family."
Friends were shocked to hear about what Jake Evans had done. They described him as a nice and shy student who was an avid golfer. He played golf for Aledo High School where he was a student until he and his sister withdrew in January to be home schooled.
"I just want people to know this action is not how we all know him," Cole Wooten, who said he had been in school with Evans since kindergarten, told WFAA. "I really liked him," classmate Clint McClellen said. "Nicest kid. Quiet, shy, kept to himself, but I liked that about him."
Dr. Laurence Steinberg, an expert in psychological development during adolescence, said that it is common for others to say that there did not seem to be anything wrong with a young perpetrator. He said signs of trouble often surface in the days following an event, as an investigation unfolds.
"It's extremely unlikely that a perfectly normal 17-year-old kid would take out a shotgun and kill members of his family," Steinberg told ABCNews.com.
"There's a little bit in what he said that sounds a little psycho-pathological in a sense that he does not seem to have the emotional response to what he did," he said. "Being callous and unemotional is a classic sign of a psychopath, so maybe he has some tendencies in that direction."
But Steinberg cautioned that sometimes it can be difficult to differentiate between shock and someone who is just unemotional.
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