A young man once dubbed one of Charleston's worst criminals is one of two suspects charged with gunning down a 15-year-old boy beneath an Interstate 26 overpass last week.

Jermel Tyler Brown's killing is yet another tragic example of why state lawmakers need to reform South Carolina's broken criminal justice system to get tougher on habitual criminals, Charleston Police Chief Greg Mullen said.

"How many more Jermel Browns must die before our citizens rise up and demand that state lawmakers make changes to our criminal justice system?" he asked.

Suspect Rafael Sinclair Horlbeck, 22, recently escaped a murder charge in another deadly shooting after two key witnesses bailed out on prosecutors in March, forcing the state to dismiss the charges, authorities said.

Horlbeck was free on $50,000 bail in connection with the rape of an 8-year-old boy when he and his brother, Leon Willis Horlbeck, 32, allegedly killed Brown on June 30, Charleston police said. Brown, a student at Daniel Jenkins Academy in North Charleston, was found shot multiple times beneath I-26 near Huger Street.

Late Wednesday, the North Charleston brothers were being held without bail on murder charges at the Charleston County jail. Rafael Horlbeck also is charged with shooting a 32-year-old man in the neck Monday night in North Charleston. Police would not say whether that shooting is related to Brown's slaying.

Mullen would not discuss a possible motive for Brown's killing, but arrest affidavits state that Rafael Horlbeck had been after the victim's twin brother, Jermaine, for a $200 drug debt. Jermaine Brown told police Horlbeck gave him a week to pay up. The bill came due about the time Jermel Brown was killed, affidavits state.

A witness told police that Horlbeck approached Jermel Brown on the night of June 29 and asked where his brother was. When Brown said he didn't know, Horlbeck ordered Brown to go on a ride with him in a burgundy sport utility vehicle, affidavits stated. A witness also saw Leon Horlbeck in the SUV as it drove down Meeting Street, police said.

Witnesses told police they saw someone try to escape from a red SUV around the same time near Meeting and Huger streets. That person was dragged back into the vehicle after screaming for someone to call police. The vehicle turned left on Huger Street toward the overpass. Minutes later, the witnesses heard gunfire, arrest affidavits stated.

Brown's uncle, Daniel Simmons, said his family is well-acquainted with the Horlbeck brothers; and they have been to Jermel's home. He said he didn't know about the debt in question but it was certainly nothing that couldn't have been worked out peacefully if the Horlbecks had simply approached his family.

At an emotional court appearance Wednesday afternoon, Rafael Horlbeck denied any involvement in the killing.

"I have much love for your family," Horlbeck told Simmons. "I had nothing to do with this."

Police and city leaders, however, aren't buying Horlbeck's story. Mayor Joe Riley described him as a "drug-dealing hoodlum" with an "astonishing" criminal record for one so young. Mullen called the suspect a predator.

By 2006, when Horlbeck was just 20, police had already added him to a watch list of the city's top crime figures. The Post and Courier also featured him last year in "Law and Disorder," a series detailing how South Carolina's troubled probation and parole system allows habitual offenders to continue preying on the public.

Horlbeck was arrested for possessing a gun in July 2006 while on probation for a cocaine charge. He stayed free on probation after his firearms arrest. Three months later, he and two other men were charged with gunning down a 22-year-old man at a Hanover Street apartment building.

Assistant Solicitor Trip Lawton said prosecutors were unable to proceed with the murder charges against Horlbeck and his co-defendants because one witness refused to testify and the other recanted her story. Prosecutors decided to dismiss the charges in hope more evidence would surface rather than proceed to trial in March with a shaky case. "We couldn't run the risk of going in there with nothing," he said.

Horlbeck left jail in April after posting bail in connection with a 2006 sexual assault case in which he is accused of sodomizing an 8-year-old boy in North Charleston, authorities said.

"There could have been no question when he was freed to the streets whether he would commit crime again, and sure enough, he has done so," Riley said. "The results are predictable."

Leon Horlbeck also is no stranger to the law. He has a 16-page criminal record dating to 1994, with convictions for crack cocaine possession and distribution, breaking into cars, trespassing, disorderly conduct, simple assault, petty larceny, shoplifting, possession of stolen goods, lying to police, possession of a stolen vehicle, and a variety of traffic violations, according to State Law Enforcement Division records. He is on probation for the manufacture and distribution of cocaine.

At an afternoon press conference, Mullen thanked the community for providing valuable tips and lauded the "relentless" work of his officers, North Charleston police and the U.S. Marshals Service that led to the suspects' capture. City officials and neighborhood leaders also heaped praise on the police, but Mullen said a far greater reward would be to see the state enact changes to prevent senseless crimes that "didn't have to happen."

"It's just on and on and on," he said. "When are people going to stop talking about issues and take some action?"

Riley, Mullen and other law enforcement leaders have prodded the Legislature to enact a variety of anti-crime measures to crack down on habitual offenders, such as the Horlbecks, but the bills have repeatedly stalled. Among other things, they want the state to give police more authority to search criminals on probation and parole, put those who attempt murder behind bars for life and allow judges to deny bail to repeat offenders charged with new crimes.

Riley said he has begun carrying Jermel Brown's photograph with him to show any lawmaker who disagrees that criminal justice reform is needed.

State Rep. Wendell Gilliard, D-Charleston, said the Legislature will act if residents start calling and demanding action. City officials and neighborhood leaders urged the public to do just that, and to continue working with police to end the violence.

The Rev. Alma Dungee said the young need to be shown there is a better way and more opportunities beyond the street. "We just need to show some love and compassion to one another."