Karak police say journalist Waseem Alam was killed by his father a few days ago, after the two exchanged heated words.
The local journalist had been murdered on Karak's Batani Khel area Saturday evening.
Police said they arrested Nawaz with the help of his mobile data and with the use of modern methods, from Lakki Marwat District.
Alam's father had not been living with the family for a few years now, said police. On Saturday evening, he had called his son to Batani Khel area where they both exchanged heated words.
In a fit of rage, Alam's father opened fire on his son and killed him on the spot. Police said they were interrogating the suspect further to extract more knowledge about the incident from him.
After the murder, the journalist's mother had filed an FIR against her son's murder, prompting police to investigate the crime.
Police had said Alam's father was one of the suspects since he had neither arrived at the hospital, where his son was taken to be treated, nor had he attended his funeral.
Following his murder, Geo News spoke to Alam's widow and brother, who both said the slain journalist had never spoken of any threat to him neither did he harbour enmity towards anyone.