The death of a beloved middle school teacher that rattled a rural California community has resulted in a total of four suspects arrested, and all but one released due to insufficient evidence, according to local reports.

Sergio Martin, a 50-year-old Spanish teacher at El Monte Middle School, was shot and killed at his home in Dinuba, California, on Nov. 6, according to local ABC affiliate KFSN.

Police arrested a juvenile in connection to the grisly death shortly after finding Martin dead from multiple gunshot wounds, according to the outlet. That suspect was released from custody.

On Nov. 9, Dinuba police arrested a 20-year-old suspect, and a 21-year-old suspect the following day. Both were released, according to KFSN.

Earlier this week, 19-year-old Joseph Garcia was taken into custody and is the only suspect to remain in custody, the outlet reported.