BERLIN (AP) — A 57-year-old man has gone on trial in Germany on attempted murder charges on allegations he poisoned co-workers’ sandwiches over several years.

The man, whose name hasn’t been released in line with German privacy regulations, is accused of lacing colleagues’ lunches with substances including lead acetate and mercury.

Prosecutors said Thursday as his trial opened in the western city of Bielefeld that the man poisoned the lunches from 2015 until 2018, the dpa news agency reported.

The man, who also faces charges of causing bodily harm, was arrested in May after surveillance video showed him putting a suspicious powder on a colleague’s sandwich. Prosecutors say he was motivated by wanting to watch their physical deterioration.

One victim is in a coma with brain damage and another has serious kidney damage.