Authorities investigating the fatal stabbing outside a Nashville bar Saturday that killed two — including the brother of San Francisco 49ers back-up quarterback C.J. Beathard — announced Sunday they identified a person of interest in the stabbing.

Police did not identify any suspects but said they want to question 23-year-old Michael D. Mosley. Nashville police appealed to the public to help them find Mosley’s location.

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The stabbing outside the Dogwood Bar, a popular midtown location, resulted in the deaths of Clayton Beathard, 22, and Paul Trapeni III, 21. Both were rushed to Vanderbilt University Medical Center, where they died. A third victim, who was not identified, survived but suffered injuries to his eye and arm, the Tennessean reported.

Police viewed security footage from the bar and said they identified three men and a woman of interest, the paper reported.

Police are trying to learn more about what led up to the altercation but said it appears that the fight was over an "unwanted" advance made "by a man toward a woman in the bar."

NFL PLAYER C.J. BEATHARD'S BROTHER AMONG PAIR FATALLY STABBED OUTSIDE TENNESSEE BAR, AUTHORITIES SAY

C.J. Beathard, the 26-year-old backup quarterback on the 49ers, returned to the Nashville area to support his family and missed Saturday night's game against the Los Angeles Rams.

The Beathard brothers are grandsons of Hall of Fame football executive Bobby Beathard, and sons of country music songwriter Casey Beathard and Susan Beathard.

Head coach Kyle Shanahan reportedly rushed into C.J.'s room hoping to provide some comfort when hearing of the tragic news. He described his quarterback as "distraught" after finding out his brother had died.

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"There's not much you can say," Shanahan said, according to ESPN. "You just try to hold a person and be there for him. We tried to figure it out, what we could do and the quickest way to get him to his family. But that was probably my first time in a situation like that, but I think it's exactly what anybody would expect. There's nothing to say, and it's as tragic and as sad of a thing that can happen."

Fox News’ David Aaro contributed to this report