Complex sentence: On 13 September, the police announced on AVRO TV prgramme "Opsporing Versocht" that DNA had been found on the remains, and by 15 September they had received more than twenty new tips.
Split into simpler sentences: On 13 September, the police announced on AVRO TV prgramme "Opsporing Versocht" that DNA had been found on the remains. By 15 September they had received more than twenty new tips.