A man slaughtered his friend in Panchagarh's Tentulia upazila as he saw his friend's immoral acts with his wife early Thursday.
The deceased was identified as Johur Ali, 55, a resident of Atwari upazila.
According to locals, Idris Ali, a resident of Banglabandha area, saw his friend was involved in immoral acts with his wife at about 4.00 pm which made him furious.
He then took a knife and tried to slit Johur's throat, leaving him critically injured.
Later, locals rescued him hearing his cry for help and rushed him to Tentulia Upazila Health Complex. Johur was referred to Adhunik Sadar Hospital but succumbed to his injuries on the way.
Police recovered the body and sent it to hospital morgue for autopsy.
Model Police Station OC Abu Sayeed confirmed the matter.
Idris and his family members went into hiding after the incident.