Sergei B. Thomas started Thomas Law Group P.C. in 2016 after having worked at the Johnson Marquez Legal Group in 2014 as a senior associate. He began his legal career in 1990 as a criminal prosecutor. The prosecutorial work provided valuable court experience where Mr. Thomas tried cases to judges and juries for approximately 16 years. Mr. Thomas was known as a skilled litigator who would take on difficult cases and enjoyed success as a result of his comfort in the courtroom. While practicing as a prosecutor Mr. Thomas tried a variety of cases, including traffic, domestic violence, drug and assault and homicide cases. After being assigned to the juvenile unit that Mr. Thomas began to find a greater sense of purpose in addressing juvenile crime which often had roots in the family system and gained insight into the role of social services in the related dependency and neglect cases. 


In cases involving children, Mr. Thomas is keenly aware of the factors that allow a court to make decisions in the best interest of children and has achieved success in helping clients address resolve parenting time and grandparent visitation issues.

After leaving criminal practice, Mr. Thomas spent 8 years with a family law firm where he adapted his trial skills to the litigation of cases involving divorce, allocation of parental responsibilities, paternity, guardianship, stepparent adoptions, dependency and neglect cases, protection orders, appellate work and drafting of prenuptial agreements. Mr. Thomas criminal experience with domestic violence and protection orders, child abuse and substance abuse gives him increased skill to manage these issues in family law cases. Mr. Thomas also believes that the same case preparation strategies that created success as a prosecutor lends itself well to family law litigation.

Mr. Thomas is a Colorado native, and attended the University of Colorado at Boulder where he received a Bachelor of Arts Degree and then attended law school at the Washburn University School of Law in Topeka, Kansas where he participated in the Student Law Clinic working on civil and family law cases. Mr. Thomas is a Member of the Colorado, Sam Carey and Adams County Bar Associations. Mr. Thomas believes it is important to give back to the community and has done so consistently throughout his legal career.

Mr. Thomas understands that in divorce or parenting time disputes, clients are often fearful and upset about their circumstances. More importantly the future is uncertain with the issues that accompany many family law cases. Asset and debt division and issues regarding children are often overwhelming for clients and often leave clients feeling anxious and uncertain about the future. In high conflict cases or cases which have significant assets, these issues can become even more troubling for clients. Mr. Thomas personally understands the frustration an attorney failing to communicate or pursue a client’s interest with determination and effort, having been through the process personally. Mr. Thomas compassionately helps clients through this difficult phase of their lives works vigorously to help clients effectively reach positive outcomes.

Mr. Thomas is committed to approaches that start with discussing clear, attainable objectives and the strategies that are particular to each case in order to do whatever possible to have those objectives met. Just as importantly, clients should have an understanding of the issues in their case and the law which governs the approach of the Courts and other professionals that may be involved in a case. Incorporating these practical considerations helps reduce feelings of worry and dread. By working closely with clients and communicating effectively about their cases, clients come away with a greater sense of calm and understanding about the legal process which is often confusing, legally technical and often lengthy.

Clients often have questions as they go through their cases and communication is critically important at every stage of the case. Mr. Thomas encourages regular communication with clients through telephone or email.. By working together with clients and staff as a team clients can be assured that a priority is placed on the concerns in their case and strategies from the outset of the case allows clients to have their goals and objectives understood and put at the forefront of the case, Mr. Thomas works tirelessly for clients in order to achieve the best outcomes. Negotiating issues is often an effective way to help clients attain the best results in cases, however, if negotiations fail, as a seasoned litigator, Mr. Thomas will skillfully fight for clients in the courtroom.

Awards & Memberships

Community Involvement

Mr. Thomas had undertaken several opportunities to engage in community relate services. Mr. Thomas has served on the non-profit Jefferson County-Build-A-Generation Board for 6 years and served as the president from 2002 to 2005. The Board assessed and implemented programs to address issues with children, including school performance, before and after school care, teen pregnancy and delinquency.

In a related volunteer activity Mr. Thomas volunteered to serve as a voting board member for the Jefferson County Juvenile Review Board. The Board reviewed community placement for juveniles who had been previously incarcerated, evaluating any risks and services necessary to make decisions for appropriate placements with the input of supervising parole officers.

As a volunteer with the Lincoln Park Scholars Program from 2000 to 2003 which provided tutoring assistance to children in schools in low income areas, Mr. Thomas by assisting students with literacy, math and other basic educational skills.

Mr. Thomas has also served on the Board of Directors for the Colorado Appointed Special Advocates in Jefferson County which served children in divorce and custody cases by providing volunteers that helped supervise parenting time and provide other court related reporting regarding children.

And for the past 5 years, Mr. Thomas has served as a volunteer with Nelson Ministries, which serves food, clothing and needed items to the homeless in downtown Denver.