Many were in disbelief after learning the elderly woman, Isabel Hernandez, was stabbed to death inside her apartment by her own grandson, 23-year-old Gustavo Rios. Authorities say Rios a transient.
According to friends of Hernandez, Rios often visited his grandmother. Rios turned himself in to police Monday after admitting to them he killed Hernandez.
"During the investigation, we determined it was a homicide, the victim had died from stab wounds," said Lt. Joseph May of the Simi Valley Police Department. "Through the investigation we were able to determine her grandson, 23-year-old Gustavo Rios, a transient from Simi Valley, was responsible for her death."
Hernandez was discovered by police about 4 p.m. Sunday after officers went to check on the 75-year-old at her apartment in a senior living complex on the 1500 block of Patricia Avenue. Hernandez's family was concerned because they were unable to reach her.
Police say they have no motive as to why Rios would want to kill his grandmother.
"We don't know what the motive is. We're still conducting our on-scene investigation," said May. "We were concerned that the community would be worried that there was somebody out there. We wanted everyone to know this wasn't a random act. We have the suspect in custody."
Rios had been arrested just a few weeks ago in Ventura County for vandalizing a business.