The witness, whose name was not released, was shot four times - once in a hand, twice as he fled from his assailant, and once in the back of the neck as the gunman stood over him.
"You won't talk no more," he said just before he fired, according to prosecutors.
Crime-scene photos show blood soaking into the ground outside the witness' home, bullet casings scattered on the sidewalk. But, against all odds, the bullet missed the witness' spine. He lived to testify against Jones. Now, he is planning to testify against the men who allegedly tried to bribe him and shot him.
On Wednesday, Williams announced the arrest of Jones and three other men in connection with the shooting. Charles Alexander, 35, and Troy Cooper, 42, allegedly tried to bribe the witness, and Shaheed Williams, 21, allegedly shot him.
They face charges of attempted murder, witness intimidation, and other offenses.
The arrests capped a two-year investigation by the District Attorney's Office, Philadelphia police, and the Bureau of Alcohol, Tobacco, Firearms, and Explosives.
The arrests bring the total of witness intimidation cases city prosecutors have filed so far this year to 145. Last year, prosecutors filed 782 witness intimidation cases, down from 860 in 2012.
Since 2011, the office has filed more than 2,600 cases with witness-intimidation charges.
"We will not sit idly by and let cowards intimidate and try to murder witnesses," the district attorney said.
Intimidation remains a serious problem in the city, he said, although initiatives such as grand jury indictments - which proceed in secret - have gone a long way toward making witnesses to violent crimes feel safe enough to testify.
But the problem remains entrenched, prosecutors say. Witness statements have been posted around neighborhoods, mailed to witnesses' homes and in one case, even tacked to the wall of a Chinese restaurant.
Just last year, a 20-year-old man was sentenced to 111/2 to 23 months in prison for posting a photo of a witness statement in a gun case on Facebook and urging his followers to "kill all rats."
And in November, police found an Instagram account called "rats 215" that was posting photos and police statements of witnesses in dozens of violent crime trials across the city. One photo showed testimony apparently taken from a secret grand jury proceeding.
Local and federal authorities strive to protect and hide witnesses, particularly in violent crime cases, Williams said, adding that witness intimidation happens in virtually every homicide case in the city.
Williams said many witnesses are moved to other parts of the city, sometimes to public housing units or even hotels, but his office "can't move everyone."
The witness in Jones' case, officials said, is "safe and sound."
Jones was arrested after a 2010 case in which he fired a gun into the air during a street brawl that involved a woman he knew, Williams said. He was charged with a firearms violation for which the maximum sentence was five years in prison.
Jones would have likely received probation, Williams said, had he not allegedly sent someone to kill the witness testifying in his case.
"I want to applaud [the witness] - he is a true hero," Williams said. "He made sure justice was not denied."
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