LYNN-A Level 3 sex offender was ordered held without bail Thursday for attempted murder and other charges after he allegedly strangled his ex-girlfriend at her Kingsley Terrace home, causing her to pass out.Melvin Santiago, 34, whose last known address was the homeless shelter at 100 Willow St., Lynn, was arrested Wednesday on warrants charging him with attempted murder, domestic assault and battery, criminal harassment and seven counts of violating a restraining order.Santiago’s 43-year-old ex-girlfriend, who has taken out multiple restraining orders against him, walked into the Lynn police station on Feb. 12 with black and blue marks all over her face and a domestic violence advocate by her side, police said.The Lynn Police Department’s website lists Santiago of a Level 3 sex offender but doesn’t specify the charges for which he was convicted. However, a police report states he committed a sexual assault on a child.Police say Santiago allegedly violated the restraining order by showing up two weeks ago at the victim’s house, but the victim allowed him to stay there.At some point during the stay, Santiago allegedly became violent and choked the victim causing her to pass out and urinate on herself.The next morning, the victim told Santiago she was going to the store, but that angered him and led him to kneel on top of her, police said. She begged him not to choke her again and he eventually got up, but only after she agreed that he could accompany her to the store, according to police.The two walked to Cal’s News on Central Avenue where, at some point, she told Santiago not to return to the apartment, police said. She then went to the Willow Street homeless shelter and sought the help from a domestic violence advocate.After police took a report, a warrant was issued for Santiago’s arrest charging him with attempted murder, domestic assault and battery and violating a restraining order.Before he was arrested, Santiago allegedly called the victim six times on her cell phone, which is a violation of the restraining order.Lynn District Court Judge Michael Lauranzano ordered Santiago held without bail until a dangerousness hearing is held Tuesday.