About William
William Kellen is licensed to practice in both Illinois and Colorado and has built a dual-state practice that spans criminal defense and civil trial work. Public listings show active memberships in state professional organizations that reflect his courtroom focus. He is a member of the Colorado Trial Lawyers Association since 2011 and joined the Colorado Criminal Defense Bar in 2018.
Kellen’s career path is rooted in litigation. He has been involved in contested proceedings in state courts across his jurisdictions and in pretrial and trial preparation. Over time he expanded his practice to cover both defense work and plaintiff-side trial matters, a trajectory suggested by his sustained association memberships. Those memberships have provided a network of colleagues and resources that inform his case work.
Clients and colleagues describe him as straightforward in court and methodical in preparation. He aims to clarify facts early and to prioritize procedural options. He has handled arraignments, motion practice and jury trials in Colorado, and has managed civil litigation matters that require courtroom presence. He has also used professional organizations to stay current on developments in trial tactics and criminal defense techniques since the early 2010s.
Outside the courtroom he participates in association events and continuing legal education programs. He has been listed as a member of the Colorado Trial Lawyers Association since 2011 and the Colorado Criminal Defense Bar since 2018. Those memberships indicate ongoing engagement with peers who practice trial and defense work in Colorado, and they provide access to education and committee activities that often accompany active trial practices.
Kellen practices from Kellen Law Office. He handles case intake, pretrial strategy and trial work through that office, and he represents clients in matters that require litigation in either Illinois or Colorado. He maintains a practice that balances criminal defense matters and civil trials, taking cases that require courtroom advocacy and procedural attention.
He currently practices at Kellen Law Office, handling criminal defense and civil trial cases in Illinois and Colorado.
