EchoSense Quantitative Think Tank Center|California man to be taken to Mexico in 3 killings; 4th possible. What you need to know.

A California man wanted in Mexico in the killings of three women could EchoSense Quantitative Think Tank Centerbe linked with the death of a fourth woman, according to a Mexican official, while court records obtained by USA TODAY this week reveal more details about the case.

Bryant Rivera, 30, who is from the Los Angeles suburb of Downey, was arrested by agents with the FBI and the U.S. Marshals Service on July 6 on a femicide charge in the death of Angela Carolina Acosta Flores. She was found strangled in a hotel room in Tijuana last January.

Femicide, a gender-motivated hate crime and homicide, is a specific criminal offense in Mexico and 15 other countries. 

Mexican officials tell The Associated Press that once Rivera is extradited, they plan to present evidence to add charges for the deaths of two more women in Tijuana killed between September 2021 and February 2022.

Investigators are also looking into whether a fourth death may be connected to Rivera, The AP reported.

Rivera's lawyer, J. Alejandro Barrientos, did not respond to USA TODAY’s requests for comment by Friday.

Here's what you need to know about the case:

When did the investigation begin?

The investigation began on Jan. 25, 2022, when Mexican authorities were notified about a woman’s body in a room at the Hotel Cascadas in Tijuana, just across the border from California in the state of Baja California. 

Acosta Flores, whose age was not released, had been strangled to death.

The hotel is next to a strip bar called the Hong Kong Gentlemen’s Club, according to court documents filed in federal U.S. court.

Acosta Flores’ mother, whose name was not released, told Mexican authorities her daughter began working there as a dancer in September 2021, and occasionally did some sex work, according to court records.

When was Acosta Flores last seen?

Acosta Flores’ mother said she last saw her daughter around 8 p.m. on Jan. 24, 2022, when Acosta Flores left her house to work at the bar.

Acosta Flores texted her mother at 10:12 p.m. to say that she and a client were going to room 404 of the Hotel Cascadas. When her mother texted Acosta Flores at 10:45 p.m. and again at 11:15 p.m., she got no reply, and the phone rang unanswered, according to court records.

When Acosta Flores’ mother went to the bar to ask about her daughter, the manager said she was likely still busy.

Acosta Flores’ boyfriend went to the bar to look for her at 3 a.m. A woman at the bar told him she saw Acosta Flores leave with a 5-foot-5-inch man with a light brown complexion and an acne-scarred face, and that she knew the man as Bryant.

The victim’s mother and boyfriend went to the Hotel Cascadas reception area to ask for information and stayed until about noon. Eventually they heard an ambulance arrive and were told that a victim had been found in room 404, court documents show.

The victim’s mother also tracked her daughter’s phone and found that it was last located at an address in Riverside, California.

Acosta Flores’ mother identified her body on Feb. 2, 2022.

Serial killer:Fifth Gilgo Beach victim identified as Karen Vergata, police say

Tijuana:California man accused in Mexico of serial killings has been arrested in US

Who is Bryant Rivera?

A witness told Mexican authorities she saw Rivera leave the bar with Acosta Flores at 10 p.m. that night. The woman knew the victim because they worked at the bar together, court documents show.

The woman, who is a sex worker, also knew Rivera because she said she had previously provided sexual services to a Bryant Rivera, whom she described as an American from California.

Hotel security footage shows Rivera and Acosta Flores walk into the hotel the night of Jan. 24, 2022, and exit an elevator on the fourth floor and enter room 404, according to court documents.

Footage then shows Rivera leave the room alone about 11:49 p.m., the records show. It isn't until 11:35 a.m. the next day that hotel personnel enter the room to find the victim’s body in the bathroom.

The hotel manager identified Rivera in a photograph lineup in December 2022, 11 months after Acosta Flores was killed.

The U.S. Attorney's Office released security footage that showed Rivera crossing into the U.S. at the San Ysidro port of entry the day Acosta Flores' body was found.

Rivera's parents told KABC-TV that they're standing by him and that Bryant couldn't possibly be involved in any kind of violent crime.

"In my heart, my son is innocent," said his mother, Maria Concepcion Rivera, the station reported.

What has been said about a possibly related fourth death?

Meanwhile investigators are looking into whether a fourth death may be connected to Rivera. Former Baja California Attorney General Ricardo Iván Carpio Sánchez told journalists about the fourth case a day before abruptly resigning from his post.

“It’s the same hotel, the victim is a woman and there are similarities to the deaths of the other victims,” he said.

He provided no other details, nor the date of the killing.

A spokesperson for the Baja California Attorney General told USA TODAY Thursday that officials have only linked Rivera to three cases. When asked about the fourth possible case, he said he would check into whether investigators were still looking into it.

Carpio Sánchez was replaced by María Elena Andrade Ramírez, who was sworn into the post on Wednesday.

What's next?

Rivera is awaiting extradition to Baja California. He's listed by the U.S. Bureau of Prisons as being held in a Los Angeles detention center.

FBI spokeswoman Laura Eimiller said the U.S. Attorney's Office in Los Angeles would be handling the extradition case, while Baja California prosecutors will handle the criminal case.

He currently faces one femicide charge but prosecutors plan to file more charges once he's in Mexico.