Police identified Stephen Nicholas Broderick, 41, as the suspect, and said that he is armed and dangerous. It is unknown if he fled on foot or in a vehicle.
Local residents were advised to shelter in place during the incident. Police later described it as a domestic situation, but said the scene as “very active” on Twitter.
First responders found three adults, two Hispanic women and a Black man, with gunshot wounds. They were pronounced dead at the scene. A preliminary investigation indicated that the suspect knew the victims.
Austin-Travis County Emergency Medical Services said there were no reports of further victims.
Mr Broderick is a former Travis County Sheriff’s Office detective and was charged with the sexual assault of a child in June 2020, according to KXAN.
He was placed on administrative leave and taken into custody at Travis County jail on a $100,000 bond.
Following the shooting, there was a huge police presence on the scene near the junction Great Hills Trail and Rain Creek Parkway in the Arboretum area of the city. A heavily-armed SWAT team in military fatigues was part of the response.
The incident occurred shortly before noon at an apartment complex, a few blocks from a strip mall and Trader Joe’s grocery store.
Interim chief of police Joseph Chacon says that a child was involved, but is safe and now in custody.
A number of roads were closed off in the area and people asked to report any suspicious activity as the hunt for the suspect continues.