I figured out who the potential murderer is from my side. He hasn't appeared in my comic yet, but may I present the Gunman:
Real name: Tom Gunn (legally changed from Tom Bradford)
Weight: 215 lbs
About: Tom is a gun for hire with a stellar reputation of dedication, and a low fee. He is known to love, not the sport, but the kill. Despite this, people are reluctant to hire him for one factor: he creeps them out. He will talk to his guns in a loving, sexual manner and it has been rightfully assumed that he treats them as such in private. In fact, this is why he changed his last name...
He may be a great shot, but he leaves himself open whenever he pauses to talk to/caress his gun. Having been disarmed a few times by his targets, he has also built his body up in case he ever needs to get is hands dirty, though he remains a poor hand-to-hand fighter and knows no martial arts.
The Gunman was somebody I concocted one day while thinking of a villain to enter into a villain contest the show The Cape was running (sadly, the site wouldn't let me register to even try to submit him). I kind of went back and forth on where he's from, but I do have a universe of origin for him, though he has a good amount of interdimensional contacts that knowing his home universe is not fully needed. His design obviously has a very 90s/Liefeldian aesthetic, which I felt appropriate for such a character.
All the bad things in life only help you appreciate the good even more.