ANADARKO, Okla. (KFOR) - An Anadarko mother is feeling a whirlwind of emotions as her son was shot and killed by a Caddo County deputy on Sunday, June 19. Shirley Sink - the mother of Roy Sink, who was killed in that incident - said it was just her and her son that day when he began "breaking windows" in the living room. Roy Sink OSBI investigating deadly officer-involved shooting "I went in the house and my son said, 'Mom, can you call county? I'm breaking out windows and I need help,'" said Shirley. Because the reception near their home isn't "that great," Shirley drove to a nearby highway where she could make the call to Caddo County. At 1 p. m. , Shirley made the call, but she told KFOR she had to call the police department twice before a deputy finally showed up. When the deputy showed, Roy was swinging a weapon in the front yard, according to the Oklahoma State Bureau of Investigation. Shirley said it may have been a machete, but she doesn't believe he was doing so. As Shirley drove back to her home, she said she became a bystander to her son's death as the officer shot him down in the yard. Shirley said she tried to be with her son after watching him fall to the ground, but as she approached the property, the officer pointed a gun at her and told her "to back up. " Roy was taken to a local hospital where he was pronounced dead, according to OSBI. The family wasn't made aware of Roy's death though until hours later, said Shirley. Suspect in custody after firing gun at law enforcement in Garvin County Caddo Co. officers were on scene at the Sink house for about four hours, according to Shirley. While they were there, seven bullet casings were retrieved for evidence. Shirley added two of the casings were located by her car in front of their home and one pierced her front door, shaving the living room wall inside. Shirley didn't find the bullet damage to her house until the following day. She also found a search warrant from the District Court of Caddo County in connection to the possible crime of murder in the first degree in Grady County. The search warrant was to trace evidence including, but not limited to blood, hairs and fibers. Deputies were also in search of machetes, swords, and other edged weapons. The affidavit stated to look for any ammunition, fired projectiles, and fired cases as well as corresponding surveillance and hard drives. The search warrant was signed on June 19. Metro Tech offering free online course to prepare Oklahomans for active shooting situations Shirley told KFOR she was in shambles the day her son died, but as she continues to regain a clear mind, she has more and more questions for those who were on scene. "Why did he shoot? I mean, it happened so fast. Why?" Shirley said, devastated with how it ended. "I just want my son back. He knows I love him. His last words were 'I love you, Mom. '" According to Shirley's grandson, Jesse Sink, she found another bullet casing on the road just after 3 p. m. on Monday. She has called OSBI to make them aware of her finding. The OSBI sent a statement Monday morning saying the investigation is still ongoing. .