TOKYO — Japanese authorities have raided the apartment of a nurse who’s in custody on suspicion of fatally poisoning at least two elderly patients at a terminal care hospital.

Kanagawa prefectural police said Thursday they searched 31-year-old Ayumi Kuboki’s apartment in Yokohama, near Tokyo, for more evidence in the case.

Local media say Kuboki told police she may have poisoned about 20 patients to have them die when she was off duty.

Police say they arrested Kuboki on suspicion of killing two elderly male patients within days in September 2016 by injecting disinfectant into their intravenous drips at the hospital. Police have since investigated the case. The hospital has acknowledged a spike in patient deaths around that time.