The American Civil Liberties Union has called for systemic reform of the Mesa Police Department after recently released video shows officers using what appears to be excessive force against an African American man. 

It comes as Mesa Police Department is embroiled in several other cases of police brutality.

Attorneys for 33-year-old Robert Johnson said their client was helping a friend retrieve items from an ex-girlfriend’s apartment, when police arrived, searched them and then ordered them to sit down.

In video released to the Arizona Republic, Johnson is seen asking the officers, "Why?"

One officer responded, “[Because] it makes us feel comfortable.” Johnson: “But why?” A second officer is overheard ordering Johnson to, “Have a seat.”

Johnson took a half seated posture still leaning against the wall and chided, “Aw, yeah, you are small, you are small.”

The second officer warned Johnson, “Guess what, I ain’t going to ask you again, have a seat.”

At this point, Johnson’s attorneys say he was unarmed and in a relaxed posture when police move in and began punching him repeatedly in the head.

A third officer is overhead yelling, “Dude, dude, dude, No! Dude, they told you sit down!” As another is heard saying, “Just sit down, bro’, just sit down!”

The city has not filed charges against Johnson.

The three officers and their sergeant are on administrative leave.

Mesa's police chief has ordered an internal investigation and directed officers to avoid hitting the face, head or neck, unless they are facing active aggression.