Locke, who was fatally shot last Wednesday, was not named in the no-knock warrant, according to civil rights attorney Ben Crump. The warrant was executed on behalf of St. Paul police, who were searching for a homicide suspect.
Body camera video showed officers executing the no-knock search warrant and finding Locke, who had been sleeping under a blanket on the couch and holding a gun.
Locke is seen holding a gun as he sits up and was shot less than 10 seconds after officers entered the room, still covered in the blanket.
MORE: Bodycam video shows Minneapolis officers fatally shooting Black man during no-knock warrant
The suspect, Locke's 17-year-old cousin, was arrested Monday afternoon in Winona, Minnesota, the St. Paul Police Department said Tuesday.
Officers from the Minneapolis Police Department had been to the apartment 10 times where Locke was killed in the last seven months for 911 calls related to threats, disturbances, narcotic activity, suspicious activity and domestic abuse, according to 911 calls obtained by ABC News.
The most recent 911 calls had been placed for "unknown trouble" on Feb. 1 and a "suspicious person" on Jan. 19, according to police records.
Police had obtained a search warrant for the apartment, which belongs to a family friend of the suspect's brother, because staff at the apartment building told investigators that the suspect had a key to the unit and because he was present during numerous occasions when officers responded to 911 calls.
In a statement, Crump said the family and their legal team is aware of the arrest, adding that Locke's cousin was not in the apartment at the time of the shooting.
"All available information confirms that Amir was never a target of that investigation, of those search warrants," Crump said. "We must remain focused on the fact that Amir was an innocent young man of a raid gone terribly wrong, who is now the latest statistic and victim of the dangerous and intrusive no-knock warrant techniques that must be banned."
Over the weekend, a caravan of about 50 vehicles drove through Minneapolis demanding justice for Locke, some in front of the home of interim Police Chief Amelia Huffman, demanding that she resign from her post.
The officer who shot Locke, identified by police as Mark Hanneman, was placed on administrative leave pending the outcome of the investigation, in accordance with department policy.
ABC News' Whitney Lloyd contributed to this report.