Rape suspect caught at hospital near victim

Boston police Superintendent Bruce Holloway, who oversees the Sexual Assault Unit, said detectives were "trying to tie up some loose ends" and had tried to locate Rivera, who is homeless, between the time the identification was made and the time of the second rape early yesterday morning.

"I don't know every step they made, but I can tell you right now, they were out there," Holloway said of the detectives. "We had several locations we identified where he might be found."

On Thursday afternoon, a woman Rivera allegedly raped inside the Radisson Hotel Boston parking garage on April 19 picked him out of a police photo lineup.

"Oh my God, this is the guy on the elevator who attacked me," the alleged victim told police at about 4:30 p.m. Thursday, according to the police report filed in Boston Municipal Court.

Based on that identification, Holloway said, police had the authority to arrest Rivera if they had spotted him. Holloway also said detectives had planned to get a formal arrest warrant in court yesterday and assign the fugitive unit to try to track down Rivera.

Before he could be located, however, at about 3 a.m. yesterday, a second woman was attacked inside the same Stuart Street garage. Rivera was ar raigned yesterday on three counts of rape and other charges.

Boston police did not release any media alerts after the first assault. Asked why, police said in a statement, "We do not put out alerts until we detect a pattern and the first one was an isolated incident."

The general manager from the Radisson referred questions to the district attorney's office, and an official for the garage operator, Laz Parking, did not respond to requests for comment.

Rivera wore a hospital gown during his arraignment in Boston Municipal Court yesterday. He was arrested at Tufts Medical Center, at the same time the woman he allegedly attacked in the nearby garage was being examined by doctors. He told police he was at the hospital because he had just paid $40 to have unprotected sex with a prostitute, said Jake Wark, spokesman for Suffolk District Attorney Daniel F. Conley.

Prosecutors allege Rivera preyed on women in the early morning, attacking his two victims from behind. The rapes do not appear to have any connection to a series of sexual assaults in the North End, but investigators are examining both sets of crimes for similarities, Wark said.

Defense lawyer Joseph T. Moore said yesterday that his client is the victim of mistaken identity and was arrested because he was at Tufts Medical Center. Moore would not comment on why Rivera was being treated at the hospital.

Rivera pleaded not guilty and Judge Sally Kelly set bail at $1 million for the rape charges. She also ordered Rivera held on a probation violation for a case in West Roxbury Municipal Court. Rivera has family in the Boston area but has been homeless for the past year, Moore said. He suffers from bipolar disorder, Moore said, and receives monthly injections for the illness.

According to police and prosecutors, the April 19 attack occurred on the fifth floor of the parking garage at 5:30 a.m. The woman, who was arriving to begin her workday, was asked for directions by a man later identified as Rivera.

After giving him directions, she turned to walk away and was attacked from behind, according to the police report.

The woman started to scream, according to the police report, and the attacker threatened to throw her from the garage onto the street below.

"Do you want to die?" he asked.

The man beat her, ripped off her clothes, and raped her repeatedly, according to the report. He ran when a passerby arrived. The passerby chased the man, who escaped in an elevator.

About 3 a.m. yesterday, a woman on the second floor of the parking garage was grabbed from behind, dragged by her hair, beaten, and raped, Suffolk Assistant District Attorney Dara Kesselheim said in court.

The woman broke free and found a police officer outside. She identified Rivera as her attacker after his arrest at Tufts Medical Center, prosecutors said.

Last fall, a woman reported she had been raped, identified her attacker to Boston police and brought police to his apartment, but the alleged rapist wasn't arrested for another two weeks, after he had allegedly committed a new sexual assault.

Maria Cramer of the Globe staff contributed to this report. John Ellement can be reached at ellement@globe.com.