SACRAMENTO (CBS/AP) — Sacramento County authorities have arrested two men they say fatally shot a man and two teenage boys as they rode their bicycles through a Sacramento suburb earlier this week.

The Sacramento Bee is reporting that sheriff’s officials arrested 20-year-old Francisco Ignacio Delgado and 24-year-old Juan Isidoro Aucencio at their homes early Saturday.

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Investigators don’t know what sparked the shooting, but say the two suspects gunned down 20-year-old Robert Corpos, 16-year-old Richard Ward and 15-year-old Jamir Miller as they rode their bicycles in Rancho Cordova Sunday afternoon.

Corpos died at the scene, while the two teens died after being taken to a hospital.

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Investigators don’t know what sparked the shooting, but sheriff’s spokesman Jason Ramos says Corpos has been identified as a member of a gang.

It’s not known if the two suspects had retained attorneys.

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