Officers responded to several 911 calls from an apartment unit on Willow Avenue near Gettysburg Avenue shortly before 7 am.
The disturbance involved three family members and at one point, they say a man took out a gun and threatened another person inside the apartment.
Investigators believed the suspect barricaded himself inside that home -- but when they searched the apartment -- he wasn't inside.
A short time later, a patrol officer found the man near San Gabriel Park.
He's identified as 21-year-old Marcos Lopez.
He was taken into custody without incident and booked on several charges including false imprisonment and assault with a firearm.