MARYLAND HEIGHTS, Mo. (AP) — Authorities say a part-time janitor has been charged with first-degree murder after shooting and killing a co-worker at a crowded suburban St. Louis community center before a police officer rushed inside and exchanged gunfire with the shooter. The suspect, 30-year-old Michael J. Honkomp, was seriously wounded. Maryland Heights police Chief Bill Carson said Tuesday that the gunman was upset about being sent home when he opened fire Monday night. The building’s acting supervisor, 45-year-old Maria Lucas, was killed. Frantic patrons ran and huddled for cover. Some hid in closets while clutching weights to toss at the gunman. Carson praised the young officer who ran inside and shot the gunman, saying he may have prevented a much larger tragedy.