At a press conference, police said a warrant had been issued for Mason who was arrested in St. Cloud, Minn. and brought back to Chicago where he was charged with first-degree murder.



According to Eugene Roy, Chief of Detectives for the Chicago Police Department, Howard was a disabled Vietnam War veteran who had served three years in the war.



"Mr. Howard was a veteran of the U.S. Army. Suffered serious injuries there that led to him being disabled," said Roy.



Howard began working with a program, Safe Humane Chicago, to combat post-traumatic stress disorder in veterans at the Jesse Brown Veterans Affairs Hospital on the near west side.



"He went through a seven-week course. And really took to the program and actually became one of the leaders, and at the time of his death he was actually involved with other veterans," said Roy. "He was going to the VA Hospital...every day facilitating courses with other veterans and using the service dogs to help them get over their PTSD."



Roy said the Howard's service dog was returned to the group but is up for adoption.



Mason's criminal background includes two felony gun convictions.



In 2011, Cook County Judge Neera Lall Walsh sentenced Mason to boot camp and he received credit for serving 44 days in the Cook County Jail, records show.



In 2013, he was sentenced to 3 years in state prison on a separate gun conviction. He had also received credit for serving 98 days in the Cook County Jail, according to the records, but Roy said Mason served less than two years of that 3-year-sentence.



"There are no consequences," Roy told reporters Friday morning at police headquarters. "There are no repercussions when convicted felons are caught with handguns. They end up doing less than half of that term, they take that as a clear signal that there are no repercussions."



"We are using every tool, every strategy we can to hold gun offenders accountable," Roy added. "There's got to be a stick to go with the carrot."