Del. Heather Mizeur, an announced candidate for governor, urged Gov. Martin O'Malley Tuesday to launch an inquiry into the treatment of disabled people after the death of a man with Down syndrome during a confrontation with sheriff's deputies in Frederick County.

Mizeur, a Montgomery County Democrat, urged the governor to work with the General Assembly to develop policies to prevent incidents such as the one that killed 26-year-old Ethan Saylor.

Saylor died in January while being arrested by three moonlighting deputies in a theater for attempting to watch a movie for a second time without paying for a new ticket. The almost 300-pound man was asphyxiated while struggling against the deputies' efforts to handcuff him.

The case received national attention among advocates for people with Down syndrome.

An investigation by the sheriff's department cleared the deputies of criminal responsibility, and the Frederick County state's attorney declined to bring charges. Sheriff Charles A. Jenkins, a Republican who defended his deputies' actions, said last month that the U.S. Department of Justice is investigating the incident.

Mizeur told the governor she has become "increasingly frustrated" about what she called "a tragic case of dire importance."

While a press release issued by Mizeur called on O'Malley to launch "a full investigation and inquiry" into Saylor's death, the delegate's letter does not suggest reopening the criminal probe. She suggested an investigation by the Department of Health and Mental Hygiene into policies on dealing with people with intellectual and other disabilities and creation of a task force to develop statewide standards on their treatment.

"Ethan Saylor’s death was entirely preventable, and I know we have the tools at our disposal to ensure that another case like this never happens again," Mizeur wrote.

Takirra Winfield, a spokeswoman for O'Malley, said the governor and his staff are "aware of and troubled by" Saylor's death.

"We have been working with disability advocates to determine what additional steps the State can take to prevent a tragedy like this from ever happening again, including additional training for local and state law enforcement and a review of statewide policies. We welcome Delegate Mizeur's input into this process."

The governor has no constitutional power to investigate suspected crime but can direct the attorney general to launch a probe. Generally, however, a state's attorney's decision to close a case is final.

Mizeur and Lt. Gov. Anthony G. Brown are announced candidates for the Democratic nomination for governor in the June 2014 primary. Attorney General Douglas F. Gansler is expected to make his candidacy official next month.