Arbitration and mediation are familiar ground for Sacks Tierney’s veteran litigation attorneys, including members of the American Arbitration Association (AAA) complex, commercial construction and consumer arbitration panels.


Sacks Tierney arbitrators are experienced in matters involving construction law, commercial law, creditors’ rights, medical practice disputes, real estate valuations, contract clause disputes, shareholder member disputes, and other business-related areas. Our attorneys serve as sole arbitrators, members of three-arbitrator AAA panels, and as settlement conference judges for State Court proceedings.

  • David Tierney is a past chair of the State Bar’s ADR Section and in four separate years has ranked among Super Lawyers’ top 50 Arizona attorneys. A veteran litigator, he is experienced in mediating and arbitrating a broad range of matters. David serves on AAA’s Commercial and Construction arbitration panels and Construction Mediation Panel. He and has been listed in The Best Lawyers in America® since 2006.

  • Sharon Shively, a Super Lawyers selectee and Best Lawyers honoree, frequently serves as a mediator and arbitrator in complex, multi-party matters. Sharon is a member of two of AAA’s top arbitration panels – Commercial and Construction – as well as the AAA Construction Mediation Panel. She is experienced in matters involving construction, creditors’ rights, real estate and general commercial disputes.

  • Greg Gillis has nearly 30 years of trial experience in a wide variety of construction disputes and commercial litigation matters. He has extensive experience as a neutral in mediating construction and commercial disputes. He is the chair of the State Bar’s ADR section. Greg is a member of AAA’s commercial and construction panels of arbitrators and mediators. In addition to his AAA experience, Greg is a member of the Arizona chapter of the National Academy of Distinguished Neutrals and serves as a Judge Pro Tempore for Maricopa County Superior Court, conducting settlement conferences involving a wide variety of civil matters. He has received the Martindale Hubbell AV Preeminent® rating and has been a Best Lawyers in America® honoree since 2012 and a Super Lawyers selectee since 2014.