The following is an excerpt from the Minneapolis Police policy and procedures manual on neck restrains and choke holds. Looks like what was done was legal according to the rules.

5-311 USE OF NECK RESTRAINTS AND CHOKE HOLDS

(10/16/02) (08/17/07) (10/01/10) (04/16/12)

DEFINITIONS I.

Choke Hold: Deadly force option. Defined as applying direct pressure on a person’s trachea or airway (front of the neck), blocking or obstructing the airway (04/16/12)

Neck Restraint: Non-deadly force option. Defined as compressing one or both sides of a person’s neck with an arm or leg, without applying direct pressure to the trachea or airway (front of the neck). Only sworn employees who have received training from the MPD Training Unit are authorized to use neck restraints. The MPD authorizes two types of neck restraints: Conscious Neck Restraint and Unconscious Neck Restraint. (04/16/12)

Conscious Neck Restraint: The subject is placed in a neck restraint with intent to control, and not to render the subject unconscious, by only applying light to moderate pressure. (04/16/12)

Unconscious Neck Restraint: The subject is placed in a neck restraint with the intention of rendering the person unconscious by applying adequate pressure. (04/16/12)

PROCEDURES/REGULATIONS II.

The Conscious Neck Restraint may be used against a subject who is actively resisting. (04/16/12)

The Unconscious Neck Restraint shall only be applied in the following circumstances: (04/16/12)

On a subject who is exhibiting active aggression, or;

For life saving purposes, or;

On a subject who is exhibiting active resistance in order to gain control of the subject; and if lesser attempts at control have been or would likely be ineffective.

Neck restraints shall not be used against subjects who are passively resisting as defined by policy. (04/16/12)

After Care Guidelines (04/16/12)

After a neck restraint or choke hold has been used on a subject, sworn MPD employees shall keep them under close observation until they are released to medical or other law enforcement personnel.

An officer who has used a neck restraint or choke hold shall inform individuals accepting custody of the subject, that the technique was used on the subject.

http://www.minneapolismn.gov/police/policy/mpdpolicy_5-300_5-300?cf_chl_jschl_tk=dc2a4351e561011866eeced2abaa8cb26545036b-1591018293-0-Ada8cpjVIutTZADW1GFTo267XjcdNSd3sg5OK7VZRwaUkjFwAUHdzMk9ghG94WDpxefMWQtJOAps_WhjCXCDvk1MWhP-cX1hegd66zcY1QGhMQ3K94aXIH37pLuwQITIXfzQVOR_nsXoeu6tfq7FBvlxw14d09SmzKSuJo6E9hHuWE5wXBHPBmAHb1NQxCx6h7anY6t_7AFHDmp_kcXc8LivwKMz_-wmbgRzmrCRbeiIMceFArj__avfCZjrOkP7iJrDPiNSS7Ch_dS5GHyayS5l8hJVDls8TEGHQ2roa_nT2vZH5itomuEIlDEjcxX_1w