The killing of two people in an Oakland high-rise on Wednesday night may have been a "domestic incident," and Oakland police say they now have one suspect in custody.

A 23-year-old woman and a 44-year-old man were fatally shot inside a 33rd-floor apartment in Oakland just after midnight on Thursday morning, and crime-watchers' first instinct may have been to think it was a murder-suicide. But police said it was being investigated as a homicide, and now they say they have one suspect in custody.

"No additional details will be released at this time, as this is an ongoing investigation," the OPD tweeted Friday. "Anyone with info on this case can call 510 238-3821."

The homicides occurred in the new, 34-story 17th & Broadway apartment building at 447 17th Street, in Oakland's Uptown neighborhood. The building has 254 luxury apartments.

A tipster from a neighboring building shared some messages from a community chat app with SFist Friday in which neighbors were discussing the security of stairwells. Apparently, rumors were swirling that the assailant in the double-homicide might have accessed the 33rd floor via the stairwell, because elevators tend to be more secure, requiring key-cards or the lobby staff's control — but stairwells in these new buildings reportedly tend to be be less secure, perhaps because of fire-safety concerns.

A neighbor said he had it "on authority" that the resident in the building — the 23-year-old woman — and her guest were targeted in a "domestic incident," so now this points to a love-triangle situation.

The Oakland Police Department has not released any such details, and likely won't, but the name of the suspect and the deceased may be released soon.

Previously: Two Found Dead of Gunshot Wounds In Uptown Oakland High-rise