New Delhi, July 9 -- Expressing concern over repeated delays in a Delhi riots trial due to the absence of police witnesses, a city court has urged the commissioner of police to issue directions ensuring that summoned officers are not assigned other duties on court dates. The order, passed by additional sessions judge Parveen Singh on July 4, came after the investigating officer (IO) in a Dayalpur Police Station case was absent, citing a prefixed assignment at Bharat Mandapam for an event since July 1. The court noted that the IO had also been absent on the previous hearing on April 30 for similar reasons. "There was sufficient time with the prosecution to inform the IO well in advance who could have informed his seniors that he has to appea...