Joseph Gillies, 18, told KREM-TV, Spokane, Wash., after a court appearance Thursday he has no good reason for shooting at least four different people with blow darts in separate incidents in Pullman and Ellensburg.
"I'm sorry it's a huge regret. It's going to stick with me for the rest of my life. It's childish. It's immature. It's ridiculous," Gillies said.
Gillies, who was identified using surveillance footage from the incidents, said he and his friends practice shooting blow darts for fun.
"It wasn't a game. It'd just be like, 'Aww you're not paying attention you get one in the butt. You pull it out, laugh about it and keep going,'" Gillies said.
Gillies said he would like to apologize face to face to each of his victims, who were not seriously injured.
"My mom called me on the phone crying like, 'Why would you do this? What's going through your head?' I just told her, 'I got nothing. You got me. I'm a moron.' That's what I said to her and she started crying and it sucked," Gillies said.
Gillies faces felony assault charges and could be sent to prison for as much as five years.
Notable deaths of 2014 [PHOTOS]