All-Tech Investment Group Inc., the electronic day trading firm at the centre of the Atlanta shooting rampage, was last year under investigation for allegedly not properly disclosing the risks of day trading to potential customers. The company agreed to pay $278,000 (£169,000) to the Massachusetts Investor Protection Fund and investors in May, Dow Jones News Service reports. That settlement came after the Massachusetts Securities Division last year charged All-Tech with deceptive advertising and making unauthorised transfers of customers' funds. Mark O. Barton, the day trader who committed suicide Thursday after allegedly killing nine people in Atlanta, was a former customer of All-Tech. At the time the Massachusetts charges were levelled, the company's attorney, Linda Lerner, told Inter@ctive Week -- ZDNet's sister publication -- that the disputed comments made on the CNBC cable channel by All-Tech CEO Harvey Houtkin were not marketing or advertising, which require disclosure. The unauthorised transfers centred on one individual, she said, and constitute an "isolated incident." However, David Shellenberger, chief of licensing at the Massachusetts Securities Division, told Inter@ctive Week: "The type of alleged misconduct that we found naturally has to result in enforcement action." A gunman fitting Barton's description walked into All-Tech's Atlanta office Thursday afternoon and opened fire, killing four people, then shot and killed another five people in a nearby day trading brokerage, Momentum Securities. Police later found Barton's wife and two children dead in a Stockbridge apartment, taking the death toll to 12. Atlanta Mayor Bill Campbell said Barton "apparently was a day trader at a brokerage firm and was concerned about financial losses. He was there, noticed the market was down and pulled out a gun and began shooting." Houtkin told CNN that, according to a witness he spoke to, "he had come back in, he had a conversation today for about five minutes. He [the witness] told me he heard a few shots and knew something was wrong. The door apparently flew open and he went on a shooting spree throughout the office." Houtkin said that people come in to All-Tech's Atlanta branch office and trade stocks for their own accounts. "From what I heard from my staff here he had not traded since the end of April. So I don't think it had anything to do with a down day in the market," he said. "Dealing with the stock market is difficult enough. Dealing with something like this is a nightmare." According to reports, Barton was having marital problems. All-Tech, based in Montvale, N.J., specialises in the Small Order Execution System, the computerised do-it-yourself trading of batches of up to 1,000 shares. In some quarters, small traders who use this rapid-fire method, which accounts for up to 17 percent of the Nasdaq's daily volume, have come to be known as "SOES bandits." All-Tech's Houtkin has even written a book on the subject, "Secrets of the SOES Bandit." According to the company's site, customers need at least $25,000 to open a day-trading account. All-Tech's site also features the following statement: "Warning: Active electronic stock trading is risky. Participants should be aware of, and capable of assuming the inherent risks." To prepare potential customers for the hurley-burley of day trading, All-Tech Training Group Inc., an affiliate company part-owned by Houtkin through Rushmore Financial Services Inc., offers the Day Trading Training Program, a two week boot camp it claims is "the first formal day trading program available specialising in the utilisation of electronic order processing." ATTG's Day Trading Training Program is run at All-Tech's 22 branches, including its Atlanta offices. It's not known whether Barton took the course. All-Tech posted a statement on its site Thursday, saying that it is "shocked and saddened by the senseless tragedy." "We extend our deepest sympathies to the families of those who were killed. It is difficult to understand this kind of horrific event. No explanation can alleviate our grief or bring a sense of closure to the horror of these shootings," the statement read. Reuters contributed to this report.