Areas of Practice
  • Benjamin N. Cardozo School of Law, J.D., 1994
  • Tufts University, B.A., 1990
Judicial Clerkships
  • Hon. Allyne R. Ross, US District Court, Eastern District of New York, 1996-1997
  • Hon. John R. Bartels, US District Court, Eastern District of New York, 1995-1996
Bar & Court Admissions
  • District of Columbia
  • New York
  • New Jersey
1330 Connecticut Avenue, NW
Washington DC 20036
TEL: +1 202 429 8004
FAX: +1 202 429 3902

Daniel A. Mullen is a partner in Steptoe's Washington office, where he practices in the Energy and Financial Services Groups. 

Mr. Mullen counsels clients on energy and commodities enforcement matters and government investigations and litigation, and assists clients with the development of energy regulatory compliance programs.  He focuses on defending clients in investigations by the Federal Energy Regulatory Commission (FERC) and US Commodity Futures Trading Commission (CFTC) and has broad-based trial and appellate experience.  

Prior to joining Steptoe, Mr. Mullen served as a Division of Investigations Branch Chief within the Office of Enforcement at the FERC.  In this position, he helped develop FERC's existing enforcement regime and oversaw and conducted investigations and litigation against companies participating in the wholesale electricity and natural gas markets.  His focus was on investigations concerning energy market manipulation, reliability and other violations of FERC-jurisdictional statues, regulations and tariffs.

Mr. Mullen is a frequent speaker at industry conferences, presenting on issues related to energy and commodity enforcement defense. 


  • Chambers USA, Energy: Oil & Gas (Nationwide), 2015-2017
  • Legal 500 US, Energy: Regulatory and Litigation, 2015-2016

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