(MINNEAPOLIS) -- In a joint statement on Monday, Minneapolis' mayor and police chief sought an independent investigation into claims that city police asked emergency medical responders to sedate dozens of criminal suspects and others over the past three years with the powerful tranquilizer ketamine, according to the Minneapolis Star Tribune.
In some cases, suspects were allegedly handcuffed or otherwise restrained when they were sedated, and in other cases the individuals were not even accused of committing a crime, the Star Tribune reported.
In one case from the draft report that the newspaper cited, Minneapolis police officers and Hennepin County emergency medical personnel responded to a 911 call to find an unnamed man "who appeared to be in the throes of a mental health crisis."
Despite the man's protests, he was injected twice with ketamine and "became nonverbal and unintelligible," according to the Star Tribune.
The newspaper reported that it had obtained a copy of an unreleased draft report on the issue compiled by the city’s Office of Police Conduct Review.
The draft report said the drug “caused heart or breathing failure in some instances and suspects had to be revived or intubated,” according to the Star Tribune.
Ketamine is an animal tranquilizer that is often abused recreationally. As a powerful sedative, it has also been used as a so-called “date rape drug.”
Minneapolis officials are looking into the 2015–2017 time period in the investigation, according to the joint statement.
Minneapolis Mayor Jacob Frey and Minneapolis Police Chief Medaria Arradondo underlined the need for an independent investigation in their statement.
"To preserve public trust and ensure an impartial process -– one free of any interference, intentional or otherwise -– we will contract with an independent third party to provide the needed expertise to compliment the draft report's findings. The people of Minneapolis deserve transparency from their government," the two officials said in their statement.
The probe comes amid a dramatic spike in ketamine injections between 2012, when three such injections were documented, and 2017, when that number reached 62, according to the Star Tribune's review of the draft report.
Neither the Office of Police Conduct Review nor the Hennepin County Public Defender’s Office immediately responded to ABC News requests for comment.
The issue came to light in April, after emergency responders associated with Hennepin Healthcare, formerly Hennepin County Medical Center, began to complain of feeling pressured by police to inject the drug into criminal suspects.
On Tuesday, Hennepin Healthcare provided ABC News with a statement that pinpointed the genesis of the investigation.
Hennepin Healthcare said in the statement that based on complaints from its emergency services personnel, the hospital's director of emergency medical services contacted Minneapolis police officials in early May to "clarify that medical direction for sedation is the sole responsibility of the paramedics."
The statement went on to say that "while a police request for ketamine may occur, the final decision is always made by professional medical personnel."
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