Okanogan County sheriff's deputies and Omak police took an assault suspect into custody Wednesday morning after spending a cold night locked in a standoff, the sheriff said. The Sheriff's Department had received a tip late Tuesday that a woman had been killed at a rural methamphetamine party just south of Okanogan, Sheriff Frank Rogers said Wednesday. Deputies arrived at about midnight to find the woman, Angel Brown, alive but roughed up and lying in a mobile home. Her alleged assailant, Donald R. Nissen, 42, who was armed, had locked himself in an outbuilding, Rogers said.