The FBI will conduct a preliminary inquiry into the incident last month in which a Seattle police gang detective and a patrol officer kick a prone Latino man and use ethnically inflammatory language. The April 17 incident was videotaped by a freelance videographer and is the subject of an internal investigation by Seattle police.

The inquiry was requested by the U.S. Department of Justice, according to Special Agent Fred Gutt of the FBI's Seattle office. Gutt said such an inquiry is routine in cases where there may be a possible civil rights violation and could be followed by a full-blown investigation.

Todd Greenberg, the assistant U.S. Attorney who supervises the Seattle office's civil-rights division, declined to comment Monday.

In the video, the gang detective, Shandy Cobane, can be heard telling a man lying on a concrete sidewalk, "I'm going to beat the [expletive] Mexican piss out of you, homey. You feel me?"

Cobane, 44 and a 15-year veteran of the department, apologized for his language at a news event Friday night.

Seattle Mayor Mike McGinn, Interim Police Chief John Diaz, the City Council and Latino groups have expressed concerns about the incident. The Seattle chapter of the NAACP has called a news conference for Tuesday in which it will ask the Justice Department to intervene and will ask the city Attorney's Office and King County Prosecutor's Office to treat the incident as a hate crime.

According to KIRO-TV, which said it got the video from a freelance videographer, Seattle police officers responded to the area near China Harbor restaurant after several nightclub patrons called 911 to report an armed robbery in the parking lot. The patrons apparently described the robbery suspects as Hispanic.

The victim was able to positively identify at least one of the suspects at the scene, a police report says. Police later arrested two of the four men -- one told officers he was from Mexico while the other said he was from El Salvador, according to the police report. A third man was interviewed and released at the scene, and the fourth man was not found.

It's unknown if the man released from the scene is the same man seen in the video.

The video, shot around 2 a.m., shows a group of officers detaining three men, who are lying on a sidewalk about a half-mile from the robbery scene.

After one of the men moves a hand to his face, it appears Cobane is trying to stop the movement with his boot but ends up kicking the man's head. The man can be seen reacting, his head briefly flinching upward. Moments later, a patrol officer is seen stepping on the back of the man's leg or knee.

It was later determined that the man and another detainee weren't involved in the armed robbery, KIRO reported. The officers help the man to his feet and sit him against a patrol car. The man, who has a scrape on his head, tells the videographer: "They knocked me down and kicked me in the head."