That gruesome crime touched-off an intense manhunt and a possible break in the case. An anonymous tip led officers to a public housing building on the 400 block of Turk Street in the Tenderloin.
A man wearing a sheet over his head was escorted by police out of the public housing building Friday night.
A resident said he has seen the man there several times recently visiting another resident of the building.
He called him the leprechaun because he was short and didn't speak much.
VIDEO: Exclusive video shows person of interest in human remains case
Another man who works nearby said he recognized the man as the person of interest in pictures released by police earlier Friday.
"Yes, I recognize this person," Dexter, a witness said. "I know he shaved his hair. I (saw) his pictures on TV, and a few days ago. I saw him, and then you guys bringing this person out. It's him."
In surveillance video from a business near where the suitcase with a torso was found the man in the picture appears to be dragging a suitcase.
Police are saying that no arrest has been made and that man was just detained.
"Homicide needs to figure out whether or not this person is in fact involved in the crime aspect of this case," San Francisco police spokesperson Grace Gatpandan said. "Obviously he is a person of interest in this case; however he has not been charged with that crime."
Police found the suitcase Wednesday near Goodwill Industries on 11th and Mission streets. Inside was a headless torso. Then they discovered a leg in a garbage container in front of nearby Firestone Tires.
Police Thursday canvassed the neighborhood, combing through garbage bins, looking for the rest of the body parts. They found none.
A second man was also detained, but police didn't release any details on him.
Police said their person of interest is cooperating and will likely be questioned by police Saturday morning.
VIDEO: Raw video of person of interest in human remains case
The case remains under investigation and authorities are asking anyone with information about the death to call the San Francisco Police Department's homicide unit at (415) 553-1145 or email firstname.lastname@example.org. Anonymous tips can be left at (415) 575-4444.