Teenager requires hospital treatment after stabbing
No arrests have been made so far.
Police in Stevenage are looking for footage of a stabbing at a house party.
A 17 year old suffered a chest injury in the attack eleven days ago.
It's believed he'd been involved in a row with three other people.
Investigating officer DC Stuart Lennon said:
“We know there were a large amount of people at the party, and we are hoping that some of them may have captured the incident on their phones.
“We are also keen to speak to anyone who was at the party and who has any information which may help our investigation. You can pass on this information anonymously by going through Crimestoppers, if you would prefer.”