The police arrested the leader and a co-accused Gurveer Singh from Tarn Taran district of Punjab.
The police have recovered three weapons from them.
"We arrested Ranjit Singh Rana and one more person in wee hours of the day. Three weapons including 12 bore gun, .315 bore rifles and a pistol were recovered from his possession," Amritsar's Police Commissioner Ram Singh was quoted as saying by Hindustan Times.
The police said two other accused in the case are absconding.
Image: Wife and daughter of police official Ravinder Pal Singh, who was allegedly shot dead by a SAD (B) leader and his accomplices after he objected to them harassing his daughter, wail at their house in Amritsar on Thursday.