Denver police are searching for a man accused of unleashing a pit bull mix on a bride at her wedding reception and then beating her with brass knuckles."The whole time he just stood there and laughed," the 22-year-old bride, Brittany Cortez, said of her alleged attacker, Joel Nevarez, a troubled childhood friend."He let that dog drag me around the street like a rag doll," the bride said. "He punched me in the face and the back of the head with brass knuckles."Friends and Nevarez's family members said they live in terror of the 31-year-old man, who they said has become increasingly unstable and aggressive.Police said Nevarez is wanted on an arrest warrant for felony assault with a deadly weapon in the attack. Police said Nevarez may have fled to Mexico, where his mother lives.Instead of a honeymoon, Cortez got a trip to the hospital where she required stitches on her shoulder and down her back."I didn't deserve this on my wedding day," a weeping Cortez told 7NEWS reporter Lindsey Sablan Thursday. "How could (he) do this to me?"Cortez stressed that she had even cared for Nevarez after he was released from a state mental hospital.Given his troubled history, the bride admitted she reluctantly invited Nevarez to the wedding."I invited him to the wedding because I was afraid if I didn't, he would do something worse," she said.Police said the attack happened about 1 a.m. Sunday as the newlyweds celebrated at a Williams Street home in Denver.Brittany's new husband, Jorge Cortez-Trinidad, told police he was inside the house when he heard Brittany screaming and crying outside.Cortez-Trinidad said he rushed out to see Nevarez's pit bull mix dragging Brittany by her hair on the ground as Nevarez punched her with brass knuckles, according to an arrest warrant affidavit.The dog "wouldn't let go of me, just started dragging me back and forth while everybody at my party kicked the dog to get it off," Brittany Cortez said.Cortez-Trinidad said he was struggling to pry the dog off his bride when the dog began biting her back, the affidavit said. The groom began punching the dog and it turned and began biting him.Police said a wedding guest was also bitten during the attack.The dog has been seized and is being held on a 10-day quarantine at the Denver Animal Shelter. Its fate is undecided.Brittany and Jorge are recovering at home."It feels like the dog tried to rip my arm off," she said.The bride said she's weak, nauseated and scared that Nevarez could appear at any time.Brittany said she believes Nevarez attacked her because he's jealous of her as she moves on with her new life."I deserve so much more on my wedding. 'I did everything for you and in return. You have a dog attack me,'" she said, as if talking to Nevarez.Nevarez's sister, Monica Nevarez-Coronado, said she's frightened about what her brother might do next."I'm sleeping with my gun next to my nightstand because I am scared to just wake up and he's standing next to the bed," she said. "Who knows what he's capable of?"At the time of the wedding attack, Nevarez was on probation for a destruction of private property conviction in Denver, according to court records. He also faces a Dec. 17 trial date on a 2011 Denver assault, and was free on $5,000 bond in that case.