Detectives have arrested a 23-year-old man in Derry on suspicion of attempted murder.
It's in connection with a serious assault in the Cornshell Fields in Shantallow on Monday December 2nd last year.
A 28-year-old man was left in a critical condition in hospital after the attack.
The man remains in custody at this time assisting police with enquiries.
Police are also continuing to appeal for information relating to the assault.