Austin died Saturday night while staying at a homeless housing facility in Los Angeles.

A source with direct knowledge of the circumstances surrounding his death tells us there's no foul play suspected ... but it is believed he may have ingested a fatal amount of fentanyl. We're told an autopsy is set to be completed Monday, with final toxicology results expected in the next few months.

Austin's family issued a statement on his death, telling us he, “Was a loving, artistic, brilliant, and kind human being. Austin took great joy and pride in his acting career. He was an active Eagle Scout and graduated Salutatorian in High School. He went on to graduate from USC’s School of Cinematic Arts with a passion of directing and music producing."

The statement continues, "Austin’s younger sister, Kali, says her fondest memories with Austin were growing up on set with him, volunteering at events with “Kids With a Cause”, and backpacking together. Austin was the kind of son, brother, grandson, and nephew that made us proud and we will miss him deeply forever.”

Austin will best be remembered for his role as Theo Sipowicz for 7 seasons on "NYPD Blue." Theo was the son of the show's main character, Detective Andy Sipowicz, played by actor Dennis Franz.

There was a controversial scene from the show involving Austin back in 2003 when his character walked in on a naked Charlotte Ross in the restroom before she was about to shower.

The scene led to a ton of complaints against ABC and resulted in a $1.4 million fine from The FCC.

Austin took home some hardware during his career as well -- taking home the Young Artist Award for Best Performance in a Television Series in 2002 for "NYPD Blue". He was also nominated for Best Performance in a Voice-Over Role for his work on "Treasure Planet" the following year.

He also worked on other projects, including, "An Accidental Christmas", "Volare", and the 2000s show "According to Jim".

He was just 27.