Police: Teen killed over weekend was defending sister

The victim was identified as Ronald T. Gibbs, a boxer who reached the quarterfinals in the 2010 National PAL Championship in San Antonio and had Olympic aspirations. Marvin McDowell, president of the state's amateur boxing association, said Gibbs, known as "Rock," was at one point was ranked in the top 10 in the country.

"It's a life wasted," McDowell said. "The boy was so talented. He had a future, and just like that, his life is over. It's senseless."

Police spokesman Anthony Guglielmi said at a Monday morning briefing that Gibbs' 20-year-old sister was arguing with a man and Gibbs came outside after hearing a commotion. Both of them were stabbed by the man, who fled.

Guglielmi said police were "optimistic" on some leads in the investigation, but no arrest had been made and he could not confirm a motive.

Gibbs attended Carver Vocational Technical High School and was in the Class of 2011, according to his Facebook page.