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Named by the Calgary Herald in 2007 as a “Compelling Calgarian” to watch, Tonii has built a reputation as a tough criminal lawyer known for her strategic thinking and effectiveness in the courtroom. Over her twenty plus years as a lawyer, Tonii has dedicated her entire career to defending clients charged with criminal offences. Tonii has established herself in the legal community by representing a variety of challenging and high-profile cases. She has guarded the rights of those accused of the most severe crimes such as murder and gang-related charges.

Recently she is noted for her work with clients facing sexual assault charges. As a female lawyer, she holds an advantage in questioning female accusers on difficult details. Tonii is relentless in her pursuit to ensure that her client receives a fair trial and that her client is protected from bias.

Many of her clients facing these types of charges are men. Tonii guides each client through the criminal process with expertise and confidence, holding that no one should have to face charges as serious as sexual assault alone.

During Tonii’s career, she has managed many high-profile cases. But she devotes the same attention and dedication to each of her clients that put their trust in her. She believes every charge deserves an expert defence, as the potential consequences to each client bring lasting impacts.

Tonii’s experience in high profile cases and serious charges has developed her unique perspective to develop a strategic plan for your case to succeed, no matter the charge.

Trial Lawyer

Best Criminal Lawyers Tonii Roulston

Tonii’s background includes three years at Student Legal Assistance as a volunteer caseworker during her time at law school, as well as a year spent at Calgary Legal Guidance as an articling student. Her practice has focused primarily on representing clients, both adult and youth, at the trial level. She has successfully defended individuals against a diverse array of charges including murder, organized crime, sexual assault, impaired driving/DRE, drug offences, domestic assault, white collar crime, child pornography and internet-based crimes. Tonii takes pride in defending each of her clients with the same level of intensity and professionalism regardless of the charges they face.

Tonii has defined her career by working some of the most difficult and high-profile sexual assault cases. She recognizes that the allegation of committing a sexual assault can change your life forever. Tonii will safeguard your legal rights by thoroughly cross examining your accuser and ensuring that you are able to tell your side of the story. Tonii has attained many absolute acquittals for sexual assault cases that other lawyers did not think possible to win.

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In a recent interview, Tonii stated

“Accusations of sexual assault are the easiest accusations to make-up, because the so-called victim is automatically believed, often without proper investigation. As soon as this occurs, the accused person should contact a lawyer so that we can start our own investigation and take the offensive.”

She has real concerns regarding the “I believe you” and “Me Too” campaigns that may hinder the accused’s right to a fair trial.

Tonii has successfully defended many forms of violent offences including domestic violence and murder charges. These types of charges require a lawyer with Tonii’s skillset to consider every possible defence. If you are accused of domestic assault, she will guide you through the process and explain what is required from you to obtain a successful outcome including no criminal record.

Tonii has represented a range of murder cases. The most intricate first-degree murder cases have involved firearms, wiretap, and undercover operations by police officers. Other cases include manslaughter and assaults involving knife fights. In a particular case, Tonii was able to show that an individual was unfit to stand trial and consequently jail was avoided for a client facing a murder charge. Additionally, Tonii has achieved a withdrawal for manslaughter and second-degree murder charges by the Crown Prosecutors, along with second-degree murder charges reduced to manslaughter.

For Tonii’s work related to the infamous FOB and FK gang-related homicides, she had three first-degree murder charges reduced to one charge of second-degree murder. Additionally, she achieved an acquittal for a client facing the charge conspiracy to commit murder.

Tonii has expertly defended clients facing a wide range of drug possession charges. This includes various quantities of cocaine, ecstasy, methamphetamine, heroin, fentanyl etc. Even a minor drug possession charge can result in a criminal record, which will have a significant effect on your life. Tonii has the experience and resourcefulness to employ every defence available for your case. For instance, fighting a Search Warrant or Wire Tap, submitting a Charter Application to exclude drug evidence, arguing possession, or ensuring proper procedures were followed by the police.

“I have chosen to be a Defence lawyer, not a Crown Prosecutor, because I have always believed it is my responsibility as the Defence lawyer to protect my clients from the state and to ensure that their rights are protected at every step of the process – sometimes we are all they have.”

Criminal Law Experience

Due to her expertise, Tonii is often consulted by organizations and media to comment on developments in the law. When asked to comment by on the aggressive conduct displayed in the arrest of her client, Tonii stated,

“the concern is lack of training- if the Sheriffs or Police are to have that kind of power and discretion they need to be properly trained.”

To remain informed of the most recent developments and advancements in investigative techniques, Tonii is an active member of the National Association of Criminal Defence Lawyers (NACDL). This is the largest organization for criminal defence lawyers in the United States. She attends numerous conferences throughout the United States. Previous topics have included “Defending Drug Cases,” “Forensic Science and the Law” and “Zealous Advocacy in Sexual Assault and Child Victims Cases.” This has developed her advanced cross-examination techniques and in-depth knowledge of a variety of psychological and medical defences. The ‘Forensic Science and the Law” conference specifically included sessions on defending against expert evidence called by the Crown, DNA analysis in sexual assault charges, Drug Recognition Evaluations (DRE) for impaired driving and marijuana charges, Firearms Analysis and Cell Phone/Mobile Forensics and Pathologists in homicide charges.

Education & Background

Tonii received a Bachelor of Arts degree from the University of Calgary where she majored in Political Science and minored in Economics.

Tonii has volunteered with the Dare to Dream Program conducting mock criminal trials with junior high students at A.E Cross and G.P. Vanier schools. She has been a member of the Board of Directors at the Simon House Recovery Center. Tonii is a supporter of the Calgary Drug Treatment Court, the Alberta Adolescent Recovery Center (AARC), the Enbridge Famous Five, The International Women’s Foundation (IWF), Canadian Women for Woman in Afghanistan, YMCA Walk a Mile in Her Shoes, the Canadian Cancer Society, the Humane Society, and the World Society for the Protection of Animals (W.S.P.A). She also supports the Alberta College of Art and Design (ACAD), Contemporary Calgary, and PARKLUXE fashion events. She was recently named one of Avenue Magazine’s Best Dressed 2018.

Tonii is also a member of the Law Society of Alberta, the Canadian Bar Association, the Calgary Criminal Defence Lawyers Association, and the National Association of Defence Lawyers in United States.

Recent Criminal Cases

Our past cases prove the practical and effective results in successfully defending and negotiating criminal charges. We will provide you with a step-by-step plan to defend your charges and ideally resolve before trial. Our criminal defence lawyer’s goal is to protect your criminal record and your freedom.

R v M.
R v M.

R v M.

Offence: Sexual Assault (s.271 CC)

Result: Acquittal


Our client and the complainant met through the client’s roommate. The complainant had a prior relationship with this roommate, and they would often have sexual encounters when they were drinking. The complainant accused the client of sexually assaulting her, and he was charged. Tonii Roulston brought a Charter application, a s.276 application, a 278 application, and rigorously cross-examined the complainant at trial. Tonii was able to establish issues in the complainant’s credibility due to her intoxication and a motive to fabricate due to the sexual relationship between her and the client’s roommate. The client was found not guilty and avoided a criminal record.
R v B.
R v B.

R v B.

Offence: Sexual Assault (s.271 CC)

Result: Acquittal


Our client and the complainant were drinking at an employee party. After the party, the complainant accused our client of sexually assaulting her. Tonii Roulston brought a s.276 application and a Mills application to allow text messages between the parties to go into evidence. During trial, Tonii was able to prove that the complainant had consented through text messages and established a motive to fabricate. The client was found not guilty and avoided a criminal record.
R v H.
R v H.

R v H.

Offence: Sexual Assault (s.271 CC)

Result: Stay of Proceedings


Our client and the complainant were in an intimate relationship for two years. They first met when the client was married to his now ex-wife. The complainant accused the client of cheating on her with his ex-wife in text messages. She then accused the client of sexually assaulting her. Tonii Roulston brought a s.278 application to get the text messages admitted into evidence. After the application, Tonii was able to negotiate with the Crown and they decided to enter a stay of proceedings, leading to no conviction and no criminal record.
R v W.
R v W.

R v W.

Offence: Sexual Assault (s.271 CC)

Result: Stay of Proceedings


Our client and the complainant met at the airport where they were on the same flight. Prior to boarding, they struck a connection and started flirting. The complainant accused the client of touching her vagina while they were on the flight. Tonii brought a s.276 application to admit into evidence text messages between the client and the complainant. These text messages suggested the complainant may have consented to the client touching her. Tonii’s application was successful and the Crown entered a stay of proceedings. The client was not convicted and avoided a criminal record.
R v H.L.
R v H.L.

R v H.L.

Offence: Sexual Assault, (s.271 CC) Assault x 2 (s.266 CC), and Choking (s.267 (c) CC)

Result: Three charges withdrawn and a nine-month conditional sentence order


Our client and the complainant were undergoing a contentious divorce. The complainant accused the client of sexual assault, physical assault, and choking her. Tonii Roulston brought a s.276 and s.278 application to bring into evidence prior sexual history between the client and complainant, text messages that demonstrated the complainant consented, and evidence that she had a motive to fabricate. Tonii was able to negotiate with the Crown leading to a nine-month conditional sentence order for the choking offence and the other charges were withdrawn. The client was able to serve his sentence in the community and avoided jail.
R v D.
R v D.

R v D.

Offence: Sexual Assault (s.271 CC)

Result: Peace Bond


Our client was accused of sexually assaulting his ex-girlfriend while they were in a relationship. Tonii brought forward a Charter application arguing that the police unlawfully obtained text messages between the parties. Tonii also brought a s.276 application to bring into evidence prior sexual history between the client and the complainant. Tonii negotiated with the Crown, leading to a common-law peace bond. The client was not convicted and avoided a criminal record.