LAS VEGAS (KLAS) — A Las Vegas man accused of killing his mother on Mother’s Day reportedly told his brother, “That’s not our mom anyways,” according to an arrest report.

On Sunday, May 15, at approximately 6:30 a.m., officers with the Las Vegas Metropolitan Police Department responded to reports of a stabbing in the 6100 block of Caprino Avenue, near Jones Boulevard and Smoke Ranch Road.

According to the arrest report, the person who called 911 told the dispatcher that his mother was dead and that his brother, identified as 49-year-old Aaron Cooney, had stabbed her and pushed her into the pool.

While on the phone with 911, the caller and Aaron got into an argument, with the caller telling Aaron to get away from him and yelling that Aaron had killed their mother, police said. The caller then told the dispatcher that Aaron was destroying evidence.

Arriving officers found Linda Cooney’s body on the ground next to a pool where she had been pulled out by her son, the 911 caller, police said.

Both the caller and Aaron lived with Linda. At around 12:30 a.m. on May 15, Aaron’s brother left to walk his dog. According to the report, when he left, both Aaron and Linda were still at home, with Linda in another room.

The caller returned two hours later, and noticed that Linda was no longer in the den, but assumed she had gone to bed as her bedroom door was closed, police said.

At around 4:30 a.m., a friend of both Aaron and his brother arrived. Aaron’s brother told police that the two ate food and hung out in the garage. The friend told police that the two smoked marijuana and methamphetamine.

At around 6 a.m., Aaron asked his brother if he had a key to Linda’s room. His brother told him that he did not have a key and that Aaron needed to knock or use a credit card to open the door.

According to the report, Aaron used a credit card given to him by his brother to open the door, making a loud noise while he entered the room. The brother told police he assumed that would have woken their mother up, but that he did not hear her say anything, which he thought was very unusual.

The brother told police he heard Aaron opening Linda’s closet door where he knows numerous rifles are kept and panicked, grabbed his own handgun, and entered Linda’s room.

The report stated Aaron was startled to see his brother in the room. The brother noticed Linda was not in her bed and asked Aaron where she was.

According to the report, Aaron responded, “I stabbed her last night. She’s gone.”

Aaron’s brother then pointed his gun at him, once again asking where their mother was. The report says that Aaron then changed his story and tried to blame the incident on someone else. He then changed his story again and started repeating “I stabbed mom last night. I killed her. I killed her.”

According to the report, Aaron then told his brother, “That’s not our mom anyways. We need a new one. Not my mom, she was a robot,” before telling his brother that he was “cleaning up the mess.”

The brother then ran to the backyard and called 911. Once in the backyard, he saw Linda’s body floating face down in the pool. He jumped into the pool and pulled her body from it, observing lacerations to her upper right arm and shoulder, police said.

While he was pulling their mother’s body from the pool, Aaron asked him why he was pulling her out, then commented in a way that the brother described as “almost jokingly” that “she was clearly dead.”

While his brother was waiting for police, Aaron exited the house with an aluminum pan and a blood-soaked cloth, which the caller believed he threw into the trash. The brother then entered the house and locked Aaron out for his own safety.

When police arrived, Aaron’s brother told them that as a child, Aaron had snorted a line of battery acid which caused Aaron unnamed medical problems. According to the report, he described Aaron as an “unpredictably violent individual,” which seemed to be caused by those problems.

Aaron’s brother told police that Aaron would routinely accuse people of hurting his cats and threaten or batter them. According to the report, he told police about an incident when Aaron was arguing with Linda and swung a knife at her, stopping it “within an inch of her body.” Aaron’s brother also told police that Aaron had hit him in the head with a rock a few years prior, causing permanent disfiguration to his ear.

Police found bloodied bathmats and towels in the trash bins in the front of the house. Detectives also found blood on the wall of the master bedroom and on the floor next to the bed. The report states that there was an attempt to clean the wall and blood around the master bathroom sink.

The handle of a kitchen knife was found in the master bedroom, with the missing knife blade found inside the kitchen trashcan. Both pieces of the knife appeared to have blood on them.

Detectives also observed a “blood trail” from the master bedroom exterior door to the pool in the backyard that looked like it had been cleaned up. Police also found a second knife in a neighbor’s yard, they said.

After being detained, Aaron told police that he threw his mom into the pool “because she was stiff.” He told an officer that he needed to go to the hospital and that he was hearing voices. He told paramedics that he “didn’t do it” and that “you guys know I’m not a murderer,” before rambling that his mom had died three days ago.

Police arrested Aaron on a charge of open murder with a deadly weapon. He remained in custody at the Clark County Detention Center as of Tuesday.