Anupong Reungsawat, 29, allegedly ran over Sgt-Major Jakkri Palasin while he was directing traffic, resulting in him sustaining a serious head injury and broken shoulder and leg.
He then killed apartment landlord Somchai Thaenjantha, 52, and his wife Sangwal, 50.
Anupong told police he shot the couple because they often scolded him for being too noisy at the apartment.
He claimed the couple recently humiliated him in front of other tenants by scolding him for playing a guitar too loud.
He also claimed the couple ransacked his room.
Anupong surrendered at Taling Chan Police Station and officers from Bang Mae Nang Police Station later picked him up.
The gun was located behind a gas station as per Anupong’s confession.
Provincial Police Region 1 commander Lt-General Amnuay Nimmano attended the interrogation before Anupong was brought to re-enact the alleged crime amid tight security.
He is facing charges of the attempted murder of an on-duty police officer, stealing a police officer’s gun, double premeditated murder and carrying a gun in a public place without permission. National police chief General Somyos Poompanmuang yesterday visited Jakkri at Police General Hospital.