A series of unsolved sexual assaults in New Orleans has shaken residents in several downriver neighborhoods, and authorities acknowledged this week that some of the crimes bear striking similarities.

Speaking at a New Orleans Police Department briefing Tuesday in the 5th District, Sgt. Gary Lacabe described the possibility of a “serial guy going around” and noted parallels between an armed robbery and sexual assault over the weekend in the Upper 9th Ward and a home invasion and rape that happened Sept. 28 about two miles away in St. Roch.

In both of those cases, a masked man robbed a young woman at gunpoint before sexually assaulting her.

“What’s even more terrifying than having it happen to me is that he could be out there doing it to other people,” the St. Roch victim told The New Orleans Advocate.

Tyler Gamble, a Police Department spokesman, said Wednesday that as many as five recent sexual assaults “potentially” could be related.

Similar sexual assaults have been reported over the past three weeks in the Bayou St. John and Holy Cross neighborhoods. And an attempted rape and armed robbery was reported last month on Marigny Street in St. Roch, a short distance from the site of the Sept. 28 rape, which happened on North Villere Street.

Gamble stressed that, at this point, investigators do not have enough evidence to definitely link any of the crimes. Meanwhile, he said, the Police Department has redirected patrols to the affected neighborhoods.

“Either way, the trend is concerning, whether they’re related or not,” Gamble said. “What we’ve seen over the last few weeks are sexual assaults being reported in this particular area. We obviously want to be proactive in our investigation to catch the perpetrator or perpetrators.”

In separate interviews, the victims of the Sept. 28 home invasion and the Upper 9th Ward robbery Saturday recalled harrowing encounters that seemed troublingly similar but also differed in some respects.

Both women said they had no doubt, based on the other victim’s description, that they were attacked by the same man.

The New Orleans Advocate does not identify victims of sexual assault.

One of the victims, a 32-year-old woman, said she biked home with two male friends early Saturday morning and was in her yard on France Street when, seemingly out of nowhere, the masked man approached her. He held a gun to her head, called her a “bitch” — a word he used repeatedly — and began dragging her by her hair, she said.

The gunman robbed the woman and her two friends, throwing the woman on the ground and ordering her friends to place their hands on their heads and face away from him. He placed a gun to the head of one of the friends and demanded the PIN for his bank card, saying, “I’m not f***ing with you.”

“I don’t know why, but I kept looking him in the eye because he kept telling me not to look at him,” the woman said. “He wasn’t loud but very assertive.”

At 3:01 a.m., the woman tried to call 911 from her cellphone, but it apparently did not go through. She said the man forced her at gunpoint to perform oral sex on him.

Before leaving, the man asked whether the woman had ever been knocked unconscious and then struck her in the head.

“He could have done anything to us,” one of the women’s friends said in a separate interview. “I kept thinking somebody (in the neighborhood) was going to turn on a light, but we were in the backyard and there was no one to witness anything.”

Finally, the man left.

The woman described the gunman as a black man between 21 and 26 years old, about 6 feet tall and weighing 160 pounds.

“The whites of his eyes were so white,” she added. “They were big eyes.”

The Sept. 28 incident in St. Roch differed in that the gunman managed to slip through a window with bars on it to get into the North Villere Street home. A 27-year-old woman said she had been lying in bed looking at her phone, without her contacts in, when she looked up and saw a man “standing next to my bed pointing a gun at me.” Though she could scarcely make out the man’s appearance, she said his image would be “forever emblazoned in my mind.”

“I didn’t hear a thing,” the woman said. “He had to open two doors and come through three rooms, and he had to climb over a bunch of stuff to get through the window. He was really, really sneaky. It’s terrifying because, I don’t know if he’s ever been in my house before, but it certainly seemed that way.”

The gunman, wearing a bandana over his face, demanded the woman’s money and that of her roommate, who was not home at the time, and sexually assaulted her. As in the France Street case, he repeatedly called the woman a “bitch” and bound her hands at one point.

“He kept saying he was going to wait until my roommate came home,” she said. “I don’t know if he got spooked or gave up because she didn’t show.”

Finally, she said, the man ran off, saying, “I’m going to spare you.”

“I firmly believe he cased me or my house,” she added.

A police report said the man took about $375 and several credit cards. The woman later discovered, in reviewing her bank account, that someone tried to use her card at an ATM in the 8800 block of South Claiborne Avenue shortly after the robbery.

New Orleans police recently posted a video of that transaction on YouTube.

The police report describes the St. Roch robber as a black man with a thin build, about 6 feet tall and about 170 pounds.

Follow Jim Mustian on Twitter, @JimMustian.