Consumer prices rose 3.4% in July from a year ago, down slightly from 3.5% in June, the Labor Department said Wednesday. On a monthly basis, prices rose just 0.1% from June to July. The modest decline could ease pressure on the inflation-fighters at the Federal Reserve to raise their key interest rate to combat rising costs. Excluding the volatile food and energy categories, core inflation rose also slipped to 2.5% in July from a year ago, down from 2.6% in June. Still, oil prices remain elevated and gas prices rose in late July and August, suggesting overall inflation could accelerate next month.