Police have described the two suspects as male Asian adults wearing white shirts and blue jeans, and who allegedly fled in a dark-colored 2009 to 2012 Toyota Camry.
The newly released sketches are based on witness testimony.
Stone was stabbed on Oct. 8 outside a Sacramento, California, bar.
He was attacked while reportedly coming to the defense of a woman who was allegedly being hit by another man, witness Eric Cain told PEOPLE.
Stone was stabbed four times – in his back, liver, left lung (collapsing it), and his heart, his brother, Everett, said.
“He had to have open heart surgery to save his life from the knife wound to his heart,” Everett wrote on a GoFundMe page set up to raise money for Stone’s family.
Stone was recently released from UC Davis Medical Center following treatment for the stabbing wounds.
Stone previously sustained a serious injury while working to foil the train attack this summer. He needed surgery to reattach part of his left hand.
The Sacramento Police Department urges anyone with information regarding the stabbing to contact the dispatch center at 916-264-5471 or text a tip to 274637. Callers can remain anonymous and may be eligible for a reward up to $1,000.
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