The man, who set Civil Police Officer (CPO) Saumya Pushkar on fire a few days back, succumbed to his injuries in the hospital on Wednesday.
The deceased, identified as Ajas, had on June 15 set the victim on fire in the broad daylight.
The assailant, who was also a CPO, had also received burn injuries.
He was arrested by the police and admitted to Alappuzha Medical college where he took his last breath.