In February, Merced police found an unidentified woman’s body in a trash bin. On Friday, they arrested a suspect.

A murder mystery that began three months ago when the body of a 30-year-old Chinese immigrant was found in a trash bin in a dark Merced alleyway ended Friday with the arrest of a 50-year-old San Francisco man in a case police say involves romantic entanglements, human trafficking, and deadly violence.

Lijun Wang came to the United States from China in February 2016 and worked in an “indentured servant capacity” as a prostitute to pay off her debt to the people who helped pay her way across the Pacific Ocean. A year later, she was dead, her body dumped in a trash bin in an alleyway in the 3100 block of G Street.

Merced Police Detective Jeff Horn, the lead investigator in the case, said a three-month investigation led police to William Li, a 50-year-old auto mechanic who lives in San Francisco and works in San Mateo. Li also is involved in a group of “human traffickers.” That’s how he met Wang, according to Merced police.

“She was a victim of human trafficking brought here to work in the sex trade,” Horn said Friday in an interview with the Sun-Star.

Horn said Li is tied to “the organized crime” group in which Wang was working as a prostitute, but did not say exactly what Li’s role may have been within the organization. At some point during their time together, Wang and Li became romantically involved, but that relationship soured and possibly was ending at the time she was killed, police said.

Horn declined to say how Wang was killed but acknowledged police don’t yet understand why she was killed.

“We don’t really have a motive at this point,” Horn said.

Li was taken into custody Friday afternoon in San Mateo and transported to Merced. He was interviewed by police briefly on Friday and denied killing Wang, police said.

He was booked into the Merced County Jail without bail on suspicion of murder. The case will be turned over to the Merced County District Attorney’s Office for review.

Wang was one of many women working at numerous locations around the Bay Area, at the time of her death she’d been working and living in the San Jose area, police said.

Horn said he does not believe any other people involved in Li’s death, but also acknowledged many questions remain unanswered. One of those mysteries includes the motive for taking Wang’s body to Merced.

Police don’t know where she was killed but do not believe the homicide happened in Merced. Wang had been dead “less than 24 hours” when her body was found, according to investigators.

“We haven’t been able to find any real ties to Merced (for Li),” Horn said. “The only tie we did find is that he has a son (in high school) who has applied to come to UC Merced, but that’s all we’ve found as a connection to Merced.”

Detectives described Wang as “a victim” and possibly one of many, taken advantage of by a group of traffickers. Investigators said the women are kept in various houses around the Bay Area, staying at each house for about 10 days before they are moved again.

Horn said investigators began to make serious progress in the case once they identified Wang, which, he acknowledged, wasn’t easy. He also said officers were helped by some “physical evidence” that was found in the trash bin along with Wang’s body. He declined to elaborate on that evidence.

Investigators with the Alameda County Sheriff’s Office had investigated the trafficking group last year. That investigation, Horn said, helped Merced police track Wang’s travels and, eventually, led them to Li.

Wang had been interviewed as a victim in a human trafficking investigation in Alameda County last year. She told investigators people from the trafficking organization had taken her passport, police said.

Horn also credited detectives with the Merced County District Attorney’s Investigation Unit, as well as numerous other agencies including the Merced Gang Violence Suppression Unit, the San Mateo Police Department and the U.S. Department of Homeland Security.

This story was originally published April 14, 2017 at 7:34 PM with the headline "In February, Merced police found an unidentified woman’s body in a trash bin. On Friday, they arrested a suspect.."