SIOUX FALLS, S.D. (AP) A kidnapping trial has been delayed for the man serving life in prison without parole for killing the 2-year-old son of Minnesota Vikings running back Adrian Peterson in South Dakota.

Joseph Patterson is accused of kidnapping and assaulting the mother of Tyrese Ruffin in Sioux Falls in 2014 while awaiting trial in the boy's death. Patterson was convicted last September of second-degree murder in the October 2013 death of the boy who was the son of Patterson's girlfriend, Ashley Doohen, and Peterson.

Judge Brad Zell held a hearing Monday on whether police illegally entered Doohen's home the night authorities say she was attacked. Officers gained access with a spare key from one of Doohen's friends.

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Patterson's attorneys argued that since officers didn't have a search warrant, the search was illegal and the evidence obtained by officers should not be allowed at trial. Officer Pete Blankenfeld said authorities had Doohen's safety in mind.

''I felt it was necessary to enter the apartment to check on (her),'' he said.

Zell did not immediately rule on the matter or on a defense motion to move the trial out of Sioux Falls due to extensive media coverage of the case. He did postpone the trial from October to January, and said that if the trial is moved it would be held in Aberdeen.