Lawson Vampire Series by Jon F. Merz

The Fixer

"Meet Lawson: vampire by birth, Fixer by trade. His mission: preserve the secret existence of vampires by any means necessary. There's just one problem - his oldest enemy Cosgrove is back, killing humans and threatening to unleash an ancient unholy evil. Can Lawson stop Cosgrove and still adhere to the very laws he protects by not falling in love with a beautiful human assassin named Talya?" (From Amazon.com)

Order Info: ISBN 0786015004, Pinnacle Books, 2002

The Invoker

Order Info: ISBN 0786015012, Pinnacle Books, 2002

The Destructor

Order Info: ISBN 0786015357, Pinnacle Books, 2003

The Syndicate

Order Info: ISBN 0786015365, Pinnacle Books, 2003