A former friend of an alleged murderer in Texas says the former cop has comprised a list of people who bullied him in high school and is taking them out.

• Houston, TX — An alleged serial killer is on the loose in Texas and, according to a former friend, he is taking out the people who bullied him in high school. Joseph Pappas, a former cop in the area, has already struck and his first victim was a cardiologist named Dr. Mark Hausknecht.

According to Houston police chief Art Acevedo, Pappas is considered armed and extremely dangerous.

“This man is dangerous. This man’s capable. This man has some skills,” Acevedo said at a news conference this week. “He’s very dangerous, and we need to get him into custody.”

According to police, Pappas began selling off items on Craigslist just before the killings in an apparent attempt to raise funds for what his former friend is calling a killing spree.

The former deputy for Harris County Precinct 2 and Precinct 7 took to Craigslist to sell two bullet-proof vests, a $4,500 rifle, a pistol, a bullet-proof panel for a Crown Victoria, and furniture.

The former friend of Pappas, who spoke to WFAA on the condition of anonymity, said the killer is an expert marksmen who competed in shooting competition and has a stash of firearms. It was also confirmed that Pappas owned a business in which he taught people to shoot.

KHOU 11 Investigates also found a business registration records under Pappas’ name for a company called “Pappas Academy of Concealed Handgun Instruction.”

According to the former friend, Pappas was bullied in high school and has comprised a hit list of all the people he claims bullied him. He says the doctor was number one on that list.

“I personally do not think the doctor is the only person that he is going to target,” the friend told KHOU 11 on the condition of anonymity. “I think [Dr. Mark Hausknecht] was number one on the list. And Joe is extremely intelligent. He’s patient, he’s unassuming, he’s a deadly shooter.”

“[When we were] hanging out together, over burgers and tacos, telling stories, and he mentioned being called the ‘Greek shrimp’ in high school and ‘karma’s a real bitch,’ and one day the people who bullied him in high school would meet a day of reckoning,” the former friend said. “[Pappas] made the comment, at the time I thought it was a joke, ‘Hey, don’t worry you’re not on my list.’ Now looking back on it, it makes me queasy to think, ‘Oh wait, maybe this guy has a list.’”

According to police, Pappas’ first victim was shot once in the head and twice in the torso as he was riding his bicycle to work last month in the Texas Medical Center. Police say Pappas, who was also on a bike, rode past the doctor, then turned around and opened fire.

The former friend said Pappas is now hunting his next victim or victims.

“If there’s a bully he had in high school I would tell that person to take an unplanned vacation to Alaska,” the friend said.

According to state records, Pappas held his law enforcement position for 30 years. As KHOU reports, His service history lists him serving as a deputy constable with Harris County Precinct 2 from 1983 to 1986 and at Precinct 7 from 1986 to 1995. His service continued from 1995 to 1997 as a reserve officer for Precinct 7 and from 1997 to July 2013 as a reserve officer for Precinct 2.