Negotiations with a man in crisis on Grandview Avenue lasted around three hours.
Saint John Police were called to a home at around 3:45 Sunday afternoon.
A 48-year-old man who was believed to be intoxicated reportedly attempted to threaten a neighbour.
Police say he then returned to his home, where he was threatening self-harm.
Officers closed streets in the area and began negotiating with the suspect. Residents were also asked to remain in their homes.
At around 6:15 pm, he was arrested for assault and uttering threats outside the home.
He remains in police custody.
Police say no one was seriously hurt in the incident.
The streets have now reopened.