Overview
Dan Mullen, chair of Steptoe's Energy group, counsels clients on energy and commodities enforcement matters and government investigations and litigation, and assists clients with the development of energy regulatory compliance programs. Dan focuses on defending clients in investigations by the Federal Energy Regulatory Commission (FERC) and US Commodity Futures Trading Commission (CFTC).
Prior to joining Steptoe, Dan served as a Division of Investigations Branch Chief within the Office of Enforcement at FERC. In this position, he helped develop FERC's current enforcement regime and oversaw and conducted investigations and litigations against companies participating in the wholesale electricity and natural gas markets. Dan focused on investigations concerning energy market manipulation, reliability and violations of FERC-jurisdictional statutes, regulations and tariffs.
Dan is a frequent speaker at industry conferences, presenting on issues related to energy and commodity enforcement defense.
- District of Columbia
- New York
- New Jersey
- 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
- J.D., Benjamin N. Cardozo School of Law, 1994
- B.A., Tufts University, 1990
Areas of Work
Speaking Engagements
- "Market Price Determinations," 2026 APGA Gas Supply Conference, May 6, 2026
- "What's New at the CFTC and FERC?" FIA Commodities Conference, October 7, 2025
- "Energy Markets Anti-Manipulation Rules," Guest Lecturer, Energy Market Organization Course, Jones Graduate School of Business, Rice University, November 13, 2023
- "What's New at FERC?," FIA Forum, September 14, 2023
- "Getting Candid About Candor," FIA Webinar April, 19, 2023
- "Energy Markets: Overlap and Distinctions Between CFTC and FERC Regulation and Enforcement," FIA Webinar, February 10, 2022
News & Publications
Client Alerts
DOE Seeks Comments on Foreign Power Equipment Restrictions Under Trump Executive Order
September 11, 2026
Client Alerts
August 28, 2026
Client Alerts
Accelerating Grid Access for Large Loads
July 1, 2026
By: Daniel A. Mullen, Karen Bruni, William M. Keyser, Jennifer L. Key, David Marcou, Megan McDowell
Client Alerts
July 1, 2026
By: Daniel A. Mullen, Shaun Boedicker, David Marcou, Michael Zschokke
StepAhead: Antitrust & Competition Insights
DOJ Antitrust Approval of DOE Defense Production Act Consortium Agreements
April 27, 2026
By: Jonathan D. Janow, Daniel A. Mullen, Karen Bruni, Marc L. Spitzer
Client Alerts
April 13, 2026
Client Alerts
Three Supreme Court Cases to Watch for the Energy Industry
March 31, 2026
By: Daniel A. Mullen, Shaun Boedicker, David Marcou, Michael Zschokke
Resources
Client Alerts
Trump Administration Pursues Restrictions to Secure US Electricity Grid
May 11, 2020
By: Jeffrey G. Weiss, Daniel A. Mullen, Wendy Wysong, Ali Burney, Jacob Nelson (International Trade Assistant)
Financial Services Group Advisory
Forecasting the CFTC's 2020 Agenda
January 23, 2020
By: Daniel A. Mullen
Events
Seminars & Events
Disputes, Enforcement, and Energy Seminar
April 29, 2026
Speakers: Jarod Stewart, Karima Maloney, Jacquelyn Rex Tobin, Alex Wolf, Andrew C. Adams, Sandra Hanna, Ross Weingarten, Daniel A. Mullen
Seminars & Events
Energy Policy and Ratemaking Seminar
November 13, 2025
Speakers: Karen Bruni, Philip F. Corsello, Matthew J. Flynn, Kevin Garvey, William M. Keyser, David Marcou, Daniel A. Mullen, Marc L. Spitzer, Lisa M. Zarlenga
Seminars & Events
Brussels Symposium and Cocktail Reception
November 12, 2024
Speakers: Ruxandra Cana, Eric C. Emerson, Tyler Evans, Anne-Gabrielle Haie, Robert Klotz, Patrick F. Linehan, Eléonore Mullier, Daniel A. Mullen, Meredith Rathbone, Jeffrey G. Weiss, Charles Whiddington, Wendy Wysong
Seminars & Events
Developing an OTC Derivatives Trading Desk
October 1, 2024
Speakers: Alexandra C. Scheibe, Daniel A. Mullen
Seminars & Events
Disputes, Investigations & Regulatory Enforcement Seminar
April 17, 2024 - April 18, 2024
Speakers: Andrew C. Adams, Shaun Boedicker, Karen Bruni, N. Hunter Johnston, Karima Maloney, Daniel A. Mullen, Crystal Robles, Craig Smyser, Jacquelyn Rex Tobin, Larry Veselka, Jarod Stewart
Webinars
January 14, 2021
Speakers: Elizabeth Hurley Burks, N. Hunter Johnston, Daniel A. Mullen
Noteworthy
- Chambers Global, Energy: Oil & Gas - Regulatory & Litigation, US (2022-2026)
- Chambers Global, Energy: Electricity - Regulatory & Litigation, US (2024-2026)
- Chambers USA, Energy: Oil & Gas - Regulatory & Litigation, Nationwide (2015-2019, 2022-2026);
- Chambers USA, Energy: Electricity - Regulatory & Litigation, Nationwide (2023-2026)
- Legal 500 US, Energy: Electric Power - Regulatory and Litigation (2015-2016, 2019-2025)
- Lawdragon, 500 Leading Energy Lawyers (2025)
- Best Lawyers in America, Energy Law (2020-2022)
Previous Employment
- Division of Investigations Branch Chief, Federal Energy Regulatory Commission, Office of Enforcement (2008-2013)
Professional Affiliations
- FIA
- Energy Bar Association
- Infrastructure and Regulated Industries Section, American Bar Association