After four days, the police were still struggling to identify one of the four homeless men who were brutally killed in Chinatown on Saturday, and questions abounded about how the others ended up sleeping on the streets where they lost their lives.

Investigators generally face significant hurdles in finding information on homeless people who die, in part because they lack an address that can be used to find records and relatives. It’s been no different with this case.

The police said on Tuesday that they believe the fourth victim is a 39-year-old man, but they are withholding his name until investigators find a relative who can confirm his identity. The medical examiner’s office is checking fingerprint records, and may also have to turn to DNA in order to help identify him.

And information about the victims officials have identified has been scarce.

One of the them, Anthony L. Manson, 49, was a preacher who had started two nonprofit organizations in Mississippi that conducted outreach to the homeless. His family, based in Chicago, said they had no idea that he was living on New York’s streets.