Motive Behind Michigan Police HQ Shooting Unclear A 64-year-old man who was killed after walking into a suburban Detroit police station and opening fire on officers without saying a word was a military veteran who had health issues, authorities said Monday. Officers fatally shot Harold Joseph Collins on Sunday afternoon in the lobby of the police headquarters in Southfield, and a 50-year-old sergeant was hurt in the exchange of fire. Authorities were investigating what might have prompted the shootout, which happened on Veterans Day. A preliminary investigation indicates Collins had medical problems, but it is not clear if that had any bearing on his actions, Southfield Police Chief Eric Hawkins told reporters. Hawkins did not specify the nature of Collins' health issues, but a family member told The Detroit News that Collins had throat cancer and was unable to speak. A neighbor of Collins also told The Associated Press that he had trouble speaking. "Based on the behavior of this individual, my opinion and the opinion of the investigating officers, is that this person was struggling with some very serious internal issues," Hawkins said. Collins walked into the building about 2:20 p.m. Sunday and used a .380-caliber handgun to confront an officer seated behind bulletproof glass. "What's so unusual about this situation is that ... there were no words, whatsoever," Hawkins said. The suspect approached the front desk officer and simply stared at the officer. I was told that the suspect appeared to be staring into the distance and not a word was said. Southfield Police Chief Eric Hawkins holds a news conference Monday, Nov. 12, 2012, in Southfield, Mich., about Sunday's shooting inside the police offices, that wounded a 50-year-old officer and killed the gunman. The gunman was identified as Harold Joseph Collins, a veteran and resident of Southfield; the wounded officer was not identified. That officer sought cover and called for assistance. Other officers arrived from other parts of the building and ordered Collins to drop the weapon. Collins refused and gunfire was exchanged. Collins later died at an area hospital. Police would not confirm Monday if Collins had throat cancer, but a daughter of Collins' ex-wife, Seretha Nobles, said that was the case. "He has been very sick and suffering from cancer - throat cancer for many years," Nobles, who lives in Georgia, told The Detroit News. Collins lived alone in a Southfield apartment. Neighbor Drema Sanders, who lives in the same building, said she had just seen him at the mailboxes last Friday. Sanders said Collins had some kind of growth on the left side of his face that covered part of his mouth. "He was always respectful," said Sanders, 59. He would nod, because he couldn't really talk. Angelica Mercado, the leasing manager for the apartment building, said Collins had lived there for about 1½ years. She described him as very active. "I would never hear a complaint from him or from his neighbors about him," she said. Hawkins did not reveal the name of the sergeant who was wounded in the shoulder but said he was in stable condition Monday at a hospital. He said at least five officers were involved in the shooting, but he would not say how many fired their weapons. "We train these officers to deal with situations like this; to deal with the unusual, to deal with the unpredictable," Hawkins said. And this certainly qualified. They performed exactly like they were trained. Surveillance video that captured Sunday's shooting is part of the investigation and was not released Monday. The shooting was the second at a Detroit-area police station in less than two years. Four Detroit police officers were shot and wounded Jan. 23, 2011, by 38-year-old Lamar Moore at a west side station. Surveillance video showed Moore walking into the precinct and opening fire on the officers. He was shot to death in the exchange of gunfire. Associated Press researcher Monika Mathur in New York contributed to this report.