HOUSTON --A Houston police officer who shot and killed a Kingwood man now faces a lawsuit in federal court over the killing. Officer Ryan Gardiner shot and killed John Barnes in August 2009 while Barnes worked an off-duty security job. Police said the two scuffled and Barnes grabbed the officer's Taser and threatened to kill him, then Gardiner shot Barnes five times. One of our "closer look" reports showed Gardiner has used his Taser more than any other HPD officer. Barnes' common-law wife, Karen Echols, hopes her lawsuit changes how officers use excessive force on citizens. "I would just like some things changed where no one else has to go through this," she said. "No one else has to lose a father, a husband, a brother, you know, for something like this." HPD cleared Officer Gardiner in the Barnes killing. City attorney David Feldman told us the city will investigate the lawsuit and that they have no control over what the officer did during an off-duty job.