Man, 22, questioned on suspicion of Hatfield murder
Detectives have arrested a man in connection with the fatal stabbing of a Hertfordshire man.
A 22-year-old, from Welwyn Garden City, was detained on Thursday on suspicion of the murder of Darren Leonard.
The 24-year-old died following reports of a disturbance inside a flat in Northfield, Hatfield, on 11 July.
Det Ch Insp Mark Ross said it was believed to be "a targeted attack". He appealed for anyone with information to contact police.
Det Ch Insp Ross said police understood the incident "will be concerning" to many residents, and had neighbourhood officers working in the community for reassurance.
"If anyone has any concerns I'd urge them to contact these local officers," he said.
"In the meantime, if you know anything about the circumstances of the murder and have not yet informed police, please also get in touch."