(NewsNation) — Their nights started like millions of others out on the town in New York City, but after leaving popular gay bars on separate nights, both John Umberger and Julio Ramirez were later found dead with their bank accounts drained.

Umberger’s mother, Linda Clary, told NewsNation the criminals unlocked her son’s phone using its facial recognition software and drained $23,000 from his account.

Ramirez also had his phone and wallet stolen, and $2,000 had been transferred out of his bank account.

Umberger and Ramirez’s deaths are part of a string of druggings and robberies. There have been 14 similar incidents, according to Clary, who has wondered if they’re related.

New York police are looking into that as well.

“Some of the victims are members of the LGBTQIA+ community, however, it is believed that not all of the victims are,” the New York Police Department said in a statement.

NYPD’s Crimes Against Persons Unit, along with the Manhattan North and South Homicide Squads, are jointly working with our partners in the New York County District Attorney’s Office to investigate several incidents where individuals have been victims of either robberies or assault. Some of the victims are members of the LGBTQIA+ community, however it is believed that not all of the victims are. It is also believed that the motivation for these assault/robberies is monetary gain. The deaths of John Umberger and Julio Ramirez are currently under investigation and the medical examiner will determine their causes of death. Anyone with information in regard to this incident is asked to call the NYPD’s Crime Stoppers Hotline at 1-800-577-TIPS (8477) or for Spanish, 1-888-57-PISTA (74782). The public can also submit their tips by logging onto the CrimeStoppers website at https://crimestoppers.nypdonline.org/or or on Twitter @NYPDTips.

New York Police Department statement

At least two other New York City men say the same thing happened to them, but they survived the drugging. Tyler Burt was robbed of more than $25,000 after he was drugged at the Boiler Room in the East Village, according to the New York Times.

Oscar Alarcon had $2,000 transferred from his bank account using PayPal and Zelle apps on his phone after he claimed to have been drugged at the Ritz.

“I think it behooves everyone in New York City to go out with friends, watch each other’s back,” retired FBI agent Bobby Chacon said. “If someone goes to the bathroom, watch their drink so someone doesn’t put something in their drink.”

Michael Davila, a friend of Ramirez, said people out with him before he was killed lost track of him as the night progressed.

Davila knew something was wrong when Ramirez wasn’t answering messages.

“I remember texting Julio that morning, just saying, ‘Hey, girl, we’re concerned. Let us know that you’re OK.”

Davila says he is devastated, but now on high alert, as are many in the New York community.

Meanwhile, family and friends are left wondering why no arrests have been made in the case.

“It’s hard to arrest because they’re anonymous. We don’t really know who they are yet, at least publicly,” Chacon said.

“They operate in the shadows”