The victim, aged 16, suffered multiple injuries after he was stabbed in Milton Road, close to the junction with Albion Road, at around 12.45pm on Tuesday 15 June 2021.
Officers are continuing to pursue a number of lines of enquiry, including forensic checks and speaking with potential witnesses.
They are now able to release an image of a man who they believe can assist their investigation.
Detective Constable Kelly Tindall of North Division CID said: ‘Thankfully the victim is continuing to recover from his injuries. This was, however, a sustained and brutal assault which could easily have led to far greater harm.
‘As a result of our enquiries, we have identified a man who we think has important information on the incident and I would encourage him, or anyone who recognises him, to contact us as soon as possible.’
Officers are continuing to also appeal to witnesses to the assault, or anyone with information yet to speak to police, to come forward. This includes residents with doorbell cameras or other home security systems and motorists with dashcams, who may have been in the area.
Anyone with information is asked to call Kent Police on 01474 366149, quoting reference 46/103238/21. You can also contact the independent charity Crimestoppers anonymously by calling 0800 555111 or using the anonymous online form on their website.