Colin Proksel focuses his practice on complex litigation across a wide set of industries. With over thirteen years of experience, he has a long track record of success representing clients in both state and federal court, alternative dispute resolution processes (including mediation and arbitration), and administrative proceedings.

Colin graduated with distinction from the University of Iowa College of Law. Before joining Osborn Maledon, he served as a law clerk to the late Honorable Arthur L. Alarcón on the U.S. Court of Appeals for the Ninth Circuit and by designation in the Sixth and Eleventh Circuits. He was also a litigator at major firms in Chicago, New York, and California.

Colin is a Director on the Maricopa County Bar Association Board of Directors and a member of the City of Phoenix’s License Appeals Board.

Representative Matters


  • Won dismissal with prejudice of breach of contract claim based on terms of student handbook. Suleymanov v. Carrington College (AZ), Inc., No. CV 2022-053165 (Maricopa Super. Ct. Feb. 14, 2023).
  • Favorably settled breach of contract, breach of fiduciary duty, and related business tort claims arising out of alleged partnership agreement to build and sell a high-end spec home.
  • Favorably settled breach-of-settlement-agreement matter concerning disputed tax liabilities.
  • Won dismissal of wrongful death claims based on lack of personal jurisdiction. Schomburg v. Armstrong Cement & Supply Corp., et al., No. 2098/22060030 (Ct. Com. Pl. Phila. Cty. Sept. 30, 2022).
  • Won judgment on the pleadings on breach of contract claim on behalf of plaintiff. CSP Consultants Group, LLC v. 3BM Consulting Services, LLC, No. CV2021-013948 (Maricopa Super. Ct. Dec. 15, 2021).
  • Won motion to dismiss claims for tortious interference and business disparagement and motion to transfer claim for breach of the covenant of good faith and fair dealing under 28 U.S.C. § 1404(a) in firearm intellectual property matter. KE Arms LLC v. GWACS Armory LLC, No. CV-20-01625, 2021 WL 871736 (D. Ariz. 9, 2021).
  • Obtained voluntary dismissal with prejudice of Racketeer Influenced and Corrupt Organizations Act (18 U.S.C. § 1962(c)) and fraud claims in student loan debt resolution matter. Winkler v. GM Law Firm LLC, et al., No. CV-20-08248 (D. Ariz.).
  • Won reversal of fines imposed by the Maricopa County Flood Control District Board of Hearing Review against mining company. B.C. Sand and Rock Co. Inc. v. Flood Control District of Maricopa County, No. 1 CA-CV 19-0652, 2021 WL 58145 (Ariz. Ct. App. Jan. 7, 2021), review denied (June 30, 2021).
  • Favorably settled claims concerning alleged product defects, breach of warranty, negligence, unfair business practices, and fraud on behalf of manufacturer.
  • Obtained reversal of denial of summary judgment and remand with instruction to enter summary judgment in favor of major university in high-profile constitutional rights and tort action. Felarca v. Birgeneau, 891 F.3d 809 (9th Cir. 2018).
  • Represented Robert Daisley, former bandmate of Ozzy Osbourne, in fraud and accounting action against music publisher. Daisley v. Blizzard Music Limited (US) et al., No. 2:17-cv-01500 (C.D. Cal.).
  • Assisted multiple individuals who were injured in acts of international state-sponsored terrorism in seeking compensation from the U.S. Victims of State Sponsored Terrorism Fund under the Justice for United States Victims of State Sponsored Terrorism Act.


  • Favorably settled insurance claim against commercial general liability insurer concerning construction defects on behalf of home builder. United Specialty Ins. Co. v. Dorn Homes Inc., No. CV-18-08092 (D. Ariz.).
  • Won ruling that insurer’s advice-of-counsel defense waived work product protection for uncommunicated documents in insurer’s attorney’s file throughout entire course of the litigation against insured. United Specialty Ins. Co. v. Dorn Homes Inc., 334 F.R.D. 542 (D. Ariz. 2020).
  • Prevailed on motion to exclude portions of well-known insurance expert’s report and to prohibit testimony on related matters. United Specialty Ins. Co. v. Dorn Homes Inc., CV-18-08092, 2020 WL 4464400 (D. Ariz. Aug. 4, 2020).
  • Counseled specialty line insurer concerning pollution issues.
  • Advised insurer concerning lender-placed insurance.
  • Counseled specialty line insurer concerning reinsurance issues.
  • Prevailed in two-week hearing, in which court rejected claims of a breach of fiduciary duty and bad faith and motion for contempt for alleged failure to comply with previously confirmed arbitration award, on behalf of insurer. Arrowood Indemnity Co. v. Trustmark Ins. Co., No. 03-cv-1000, 938 F. Supp. 2d 267 (D. Conn. 2013), affirmed 560 Fed. App’x 75 (2d Cir. 2014).
  • Defended large provider of property and casualty coverage for Catholic Church entities in tort and coverage actions arising out of alleged clergy abuse. Whalen v. Catholic Mutual Relief Society, No. DDV-2012-9756 (Mont. 1st Jud. Dist. Ct., Lewis & Clark Cnty.).
  • Won summary judgment against reinsurer in a matter relating to purported offsets on behalf of insurer. Clarendon National Ins. Co. & Clarendon America Ins. Co. v. Trustmark Ins. Co., No. 09-cv-9896 (S.D.N.Y. Jan. 13, 2012).
  • Represented reinsurer in action to disqualify arbitrator and for preliminary injunction. Trustmark Ins. Co. v. Clarendon National Ins. Co., No. 09 C 6169 (N.D. Ill. Feb. 2010).
  • Represented reinsurer in fraud suit regarding concealment of evidence material to adverse award in prior arbitration and motion to enjoin related arbitration. Trustmark Ins. Co. v. John Hancock Life Ins. Co., No. 09-cv-3959 (N.D. Ill. Jan. 2010).
  • Defeated reinsurer’s attempt to reduce its obligations under an arbitration award for debts allegedly due to it from prior, unrelated matters on behalf of insurer. Trustmark Ins. Co. v. Clarendon National Ins. Co., No, 09-C-1673, 2009 WL 4043110 (N.D. Ill. Nov. 20, 2009).
  • Represented insurer in multiple arbitrations concerning workers’ compensation losses.


  • Favorably settled claims of tortious interference with contractual relations and civil conspiracy arising out of employment dispute.
  • Won summary judgment on behalf of employer against former employee’s Employment Protection Act claim based on admissions obtained in deposition testimony. Nelson v. Newmark Knight Frank, No. CV-17-03150, 2019 WL 6875469 (D. Ariz. Dec. 17, 2019).
  • Won dismissal on behalf of employer of former employee’s breach of contract and promissory estoppel claims. Nelson v. Newmark Knight Frank, No. CV-17-03150, 2018 WL 6435766 (D. Ariz. Dec. 7, 2018).

Telephone Consumer Protection Act (TCPA)

  • Favorably settled TPCA putative class action. Mujahid v. Divvymed, LLC, No. CV-19-05454 (D. Ariz.).
  • Favorably settled TPCA claim. Vondran v. Costco Wholesale Corp., et al., No. CV-18-01524 (D. Ariz.).
  • Favorably resolved TPCA claim. Hassen v.  Tryke Companies LLC, No. CV-18-03725 (D. Ariz.).

Pro Bono

  • Won appeal requiring Department of Health Services to amend the gender marker on appellant’s birth certificate. In the Matter of S.G., No. 2020C-OVR-0028-DHS (O.A.H. Feb. 7, 2022).


  • Best Lawyers®, Commercial Litigation, 2022-2024