TRENTON, N.J. (WPVI) -- A paraplegic man was stabbed to death inside his Trenton, New Jersey home back in 2012 and his killer remains at large.



Ikime Melvin was 32 years old when he was stabbed to death in his wheelchair.



"It's just the way it happened. It was just so brutal and senseless," said his mother, Darlene.



She acknowledges her son had his troubles and he'd been known to deal drugs. He was paralyzed from the waist down after being shot in the street by a masked man back in 1998.



Darlene keeps Ikime's ashes and photos of him at a shrine in her home, tortured that his killer is still on the loose and that her son sat helpless in his wheelchair unable to get up to defend himself.



"Why did you pull him out of the wheelchair? He couldn't walk. Why'd they have to do that to him like that?"



Ikime Melvin's is one of about 175 cases being investigated by the Mercer County Prosecutor's Homicide Task Force, which works on current and cold cases going back to 1980.



"As cases get older they're not forgotten about. I don't particularly care for the terminology "cold case." What I like to say is: 'It's an unsolved case,'" said Sgt. Chris Doyle.



Detectives say as time passes it's more difficult to solve cases: people won't share information, memories fade. But just one lead from the public can crack a case wide open.



"They might be able to provide the piece of the puzzle that's missing, that they might not think is an important piece of the puzzle but, ultimately, it may be a major factor," said Det. Jason Snyder.



"I know that someone knows something," Darlene said.



And that's why Darlene Melvin and homicide investigators are asking anyone with information about this Ikime's murder - or any other unsolved case - to come forward with information.



