Sheppard, Mullin, Richter & Hampton LLP is proficient in acting for domestic and multinational clients in antitrust investigations, prosecutions, and enforcement actions. The team’s strong expertise with matters related to the technology sector is noteworthy, as is its focus on the intersection of antitrust and intellectual property law, which extends to topics such as patent pooling, product distribution and licensing restraints. The group is based in Washington DC and headed by Leo Caseria, whose multifaceted workload includes federal and state cartel investigations, and former DOJ official Ann O’Brien, who is recommended for the whole range of domestic, international, and multi-agency cartel matters, including federal jury trials.

Legal 500 Editorial commentary

Testimonials

Collated independently by Legal 500 research team.

  • ‘I found the team that handled my case professional, caring and insightful. I felt very safe in their hands, despite being in a very stressful situation.’

  • ‘Ann O'Brien is incredibly smart, considerate and supportive, keeping me informed and answering my questions. She understood that being from another country, I needed more explanations than people familiar with the US justice system.'

  • ‘Sheppard Mullin’s cartel defense practice has defended multinationals in some of the largest U.S. civil antitrust cartel proceedings in the nation’s litigation history. With the addition earlier this year of former DOJ Antitrust Division’s Ann O’Brien, D.C. attorneys have a laser focus on the criminal component of U.S. antitrust law.'

  • 'Sheppard Mullin is one of the top firms for criminal no poach issues, helping clients like us through compliance review, investigation, or litigation services.’
  • ‘Ann O’Brien did a fantastic job.'

Key clients

  • Essex Property Trust
  • CalPortland Company
  • Hartford HealthCare Corporation
  • The Reynolds and Reynolds Company
  • JRK Residential Group, Inc.
  • Cyient
  • Export Packers Company
  • J&J Worldwide Services

Work highlights

  • Represented Hartford Healthcare in litigation filed by Saint Francis Hospital and Medical Center in January 2022, claiming that Hartford HealthCare violated the Sherman Act and Connecticut law by acquiring physicians and physician practices, and demanding that they refer their patients only to Hartford HealthCare.
  • Represented CalPortland in its antitrust claim against the four major US railroads (Union Pacific, BNSF, CSX, and Norfolk Southern), related to an alleged scheme to fix fuel surcharges.
  • Represented Cyient in a U.S. Department of Justice criminal investigation involving allegations of an alleged criminal antitrust no-poach agreement among Pratt & Whitney, Cyient, and four other outsource suppliers.

Lawyers

Next Generation Partners
Junior partners with significant recognition from clients and peers in the market and key roles on multiple matters.

Practice head

The lawyer(s) leading their teams.

Leo Caseria, Ann O'Brien