The person was arrested in his absence already on Friday but was arrested on Monday.
The suspect is a man in his 25s.
He is reasonably suspected of stabbing a woman in her 80s on July 18.
She was found badly injured at Hästhagsudden near Stafsinge beach, northwest of Falkenberg's center.
Initially, a man in his 50s was arrested on suspicion of the crime.
But the suspicions against him were later dispelled.
It is unclear whether the man now in custody has connections to the woman.
GT was the first to report on the news.