Sirena Castillo

Partner and Director of Pro Bono

Contact

scastillo@manatt.com
Phone: 310.312.4336

Services

Lead counsel representing a class of abused, abandoned or neglected children in California seeking Special Immigrant Juvenile Status (SIJS) protections.

Representing a leading medical supplier in connection with a False Claims Act investigation by the Southern District of New York.

Representing a foreign financial institution in connection with a U.S. Department of Justice Offshore Tax Compliance investigation across several international jurisdictions.

Lead associate on several internal investigations for a large teaching hospital regarding potential False Claims Act violations.

Lead associate representing an oncology practice in a criminal investigation related to billing practices.

Member of the defense team representing a health insurer in a complex multiyear contract dispute with a hospital system.

Member of the defense team representing ticketing companies in a consolidated putative class action alleging deception in online sale of tickets.

Speaking Engagements

Speaker, “Language Access: Brainstorming & Best Practices,” Association of Pro Bono Counsel at Equal Justice Conference, May 8, 2024.

Speaker, “The Benefits and Pitfalls of Temporary Immigrant Relief,” HIAS, November 15, 2023.

Speaker, “Recognizing Federal Procurement Fraud: An Overview and Practical Insights,” Virginia Procurement Technical Assistance Center (Virginia PTAC), November 19, 2020.

Speaker, “Federal Procurement Fraud Overview and Practical Insights,” Northern California Procurement Technical Assistance Center (Norcal PTAC), October 22, 2020.

Speaker, “Creating Change—The Public and Private Sector Attorneys Transforming Law and Policy Through Advocacy,” Women Lawyers Association of Los Angeles, June 24, 2020.

Honors & Awards

The Best Lawyers in America, 2022–2025

California Lawyer Attorney of the Year (CLAY) Award 2020, Daily Journal

Public Counsel Law Center’s Pro Bono of the Year 2011, Immigrants’ Rights Project

Admitted to practice in the state of California

Admitted U.S. District Court for the Central District of California

Admitted U.S. District Court for the Northern District of California

Admitted U.S. District Court for the Eastern District of California

Admitted U.S. Court of Appeals for the Ninth Circuit

Member, American Bar Association

Member, Association of Pro Bono Counsel

Member, Women’s White Collar Defense Association

Member, Lawyers’ Committee for Civil Rights of the San Francisco Bay Area

Access to Justice Editorial Advisory Board, Law360, 2022-24

Quoted, “Firms help small businesses struggling through pandemic,” Daily Journal, December 7, 2021.

Quoted, “Going to Bat for Immigrant Kids Brings Broader Impacts on Humanitarian Relief,” Daily Journal, May 13, 2020.

"Associate Perspective: What I Wished I Learned in Law School," California Litigation, Vol. 25, No. 1, 2012.

11.05.24

Castillo Quoted in National Law Journal on Manatt’s Election-Related ...

Manatt Partner and Director of Pro Bono Sirena Castillo was quoted with the National Law Journal about the Firm’s election protection ...
08.15.24

87 Manatt Attorneys Named to 2025 Best Lawyers Guide

Eighty-seven Manatt attorneys have been named to the 2025 edition of Best Lawyers in America, which recognizes the nation’s leading ...
07.25.24

Manatt Obtains Asylum for Afghan Shi’a Sadat Muslim Client

Manatt secured asylum for an Afghan Client, SM, who escaped Afghanistan as part of Operation Allies Welcome and sought asylum before the United Sta...
06.03.24

Manatt Obtains LPR Status for Former U.S. Embassy Member From Afghan ...

A Manatt pro bono team successfully obtained legal permanent residence status for a former employee of the United States Embassy in Afghanistan and...

Show More

02.07.22

The Fourth Circuit Raises the Bar for Proving Scienter Under the ...

On January 25, 2022, the U.S. Court of Appeals for the Fourth Circuit issued an important opinion for companies trying to navigate the complex ...
08.20.20

California Supreme Court Provides Seven-Factor Test for Motions to ...

On August 13, 2020, the Supreme Court of California issued its decision in Facebook, Inc. v. Superior Court (Lance Touchstone), S245203, which ...
03.28.13

BSA Compliance Fails, Go to Jail

For many years the government has encouraged directors and officers of corporations to ensure that they have robust compliance programs to detect and ...

11.15.23

Castillo to Speak on HIAS Panel About TPS Immigration Relief

Manatt Partner and Director of Pro Bono Sirena Castillo will be speaking on an HIAS panel titled “The Benefits and Pitfalls of Temporary ...

06.30.20

Risky Business: Federal Procurement Fraud in a COVID-19 World

Federal contractors weren’t excluded from the huge federal funding initiatives rolled out to defeat COVID-19 and its impact. Whether under the ...