A 14th suspect was arrested Sunday in the caught-on-camera machete killing of a 15-year-old boy outside a bodega in the Bronx in June.

Frederick Then, 20, turned himself in to police in the June 20 killing of Lesandro "Junior" Guzman-Feliz, which captivated the nation for its brutality and the apparent mistaken identity of the victim.

Then was charged with murder, manslaughter, two counts of gang assault, conspiracy and criminal possession of a weapon. He pleaded not guilty to murder charges in a court appearance on Monday. He was ordered held without bail and is due back in court Oct. 25.

As Then was walked outside by police, he told reporters: "I'm innocent." 

Video shows the teen being dragged outside the bodega and attacked by a gang of five men who stabbed him with knives and hacked him with a machete as he struggled to defend himself.

The boy was slashed in the neck and died after running to a hospital three blocks away. Thirteen other suspects have been arrested in the teen's death; all are alleged gang members. 

Guzman-Feliz had been part of the NYPD's Explorers program, a group for youths interested in a law enforcement career. The New York City Police Foundation announced it planned to set up a scholarship in his name.

Authorities say they do not believe Guzman-Feliz was affiliated with any gang.

It wasn't immediately clear whether Then had an attorney.