A 25-year-old Santee man was arrested on suspicion of murder after his grandfather was found dead at a home in the 10800 block of Grand Fork Drive, according to Patch, citing the San Diego County Sheriff's Office.

Deputies responded around 2:10 p.m. Sept. 14 to a report of an assault with a deadly weapon. They found Gregory Roundy suffering from traumatic injuries, and paramedics pronounced him dead at about 2:30 p.m., according to the report.

The Sheriff's Office identified the suspect as Derek Spratley, 25, of Santee. Patch reported that Spratley was found on the property with visible injuries, taken to a hospital, medically cleared the same day and booked into San Diego Central Jail.

Authorities said the circumstances and motive remain under investigation. The Sheriff's Office said the incident appeared to be isolated and that there was no ongoing threat to the community.

Anyone with information was asked to call the Sheriff's Homicide Unit at 858-285-6330 or, after hours, 858-868-3200. Anonymous tips can be submitted to San Diego County Crime Stoppers at 888-580-8477.