BALTIMORE (WJZ)—The three young men charged with killing an innocent 12-year-old boy in East Baltimore face life in prison. And together they faced a judge on Tuesday morning.

Mike Hellgren was in the court for their plea.

The defendants told a judge they were not guilty. A jury will determine their fate in late August.

Sean Johnson loved football, was close to his mom and did well in class.

And like a typical 12-year-old, he was hanging out with friends on a porch in East Baltimore last May.

Then, tragedy struck.

Police say 21-year-old Antwan Mosely, 17-year-old Derrick Brown, and 29-year-old Danyae Robinson shot him four times, believing he was someone else.

The three pleaded not guilty on Tuesday morning.

Those who showed up in court to support them, had little to say–as emotions ran high.

Hellgren: “You want to say that again?”

Woman:  “Yeah, I said kiss my a**. Don’t record me.”

Witnesses were reluctant to come forward, and cops used phone records to crack the case, which went unsolved for almost a year.

Police say the young men just opened fire, and left Johnson for dead on the pavement. He was hospitalized for two days before he passed.

“I can’t imagine somebody just going on his porch to watch basketball with friends and getting killed like this.  It’s just so sad,” said Stephen Gewirtz, community court watch volunteer.

“Just stop the violence.  That’s all I ask.  Shouldn’t no parent feel the pain that I’m feeling right now,” said the victim’s mother, Shawnta Little, in a November 2011 interview.

City councilwoman Mary Pat Clarke was in court for the plea. She says it’s critical to stay on the case, as it moves through the justice system.

“We’re trying to compensate, but you can’t compensate for a life lost–especially Sean’s promising life,” Clarke said.

Mosley told the judge he wanted to raise money to hire his own private attorney.  He did not want the services of the public defender.  The judge told him it would be unwise to move forward without council.  He said he understood the risks and was willing to take them.

This was one of the first cases for the City State’s Attorney’s year-old major investigations unit, which targets repeat violent offenders.