It's the same home where 26-year-old Gemmel Moore was found dead of a methamphetamine overdose in 2017. Back then, the district attorney's office found no evidence to suggest Ed Buck was responsible for Moore's death.
Friends identified the most recent victim as Timothy Dean, 55, of West Hollywood.
Dean's roommate, Ottavio Taddei, just learned of the man's death upon arriving back home from Italy.
"I don't really know what to tell you. He was a wonderful person. He's always been super nice to me," Taddei said.
A friend from the neighborhood was in tears upon hearing the news and described Dean as "the nicest, kindest man."
On Wednesday in downtown Los Angeles, a Black Lives Matter protest was held outside District Attorney Jackie Lacey's office. Moore's godbrother said Buck preys on black men who are usually young and vulnerable. He is urging Lacey to file charges against Buck.
"Ed Buck is a danger to society, not just because of what he's doing to black men, but what he's exposing our community to in general. He's exposing our community to being hooked on crystal meth and other drugs," Jerome Kitchen said.
A cause of death has not been released for Dean, but law enforcement are conducting another investigation that stems from Buck's apartment.
"I lived with him and he never did drugs. I've never seen him on drugs - ever," Taddei said.
On Monday, neighbors said waking up to another death investigation makes them uneasy.
Buck's attorney, Seymour Amster, said his client has not been arrested and the investigation is still underway. He said Monday that an old friend of Buck's showed up to his apartment under the influence and died. He added Buck did everything he could to help the man.
Amster said Buck was not high and it's just an unfortunate situation.
"An old friend of Buck's came over and was reluctant to have him come over. The individual came over, had already been partying, apparently had already been taking substances," Amster said.
"There are some individuals in our society who have a huge heart, maybe bigger than what they should have, and they allow individuals to come over when they probably...some of us would not allow them to come over, and then things happen thereafter. Not being involved in their death, trying to help them and counsel them, to change their ways - but this is what happens."
Activists said the second overdose was preventable.
"It's clear that there's a pattern and a practice of Ed Buck to prey on vulnerable, young, black, gay men who are homeless, who are HIV positive, who he can manipulate with his money, and they end up dead inside his house," activist Jasmyne Cannick said. "No matter what Ed Buck's attorney tries to spin it and say, it is very clear that Ed Buck plays a role in these young men's deaths. He needs to be stopped. It's time for Jackie Lacey to do her job and to prosecute Ed Buck."
During the protest on Monday, the activists also held a vigil for the man who died. They also turned to Buck's neighbors and said they're complicit in the deaths.
Authorities later said they are doing a secondary review of Moore's death investigation.
Buck has donated tens of thousands of dollars to Democratic candidates, including Barack Obama and Hillary Clinton. He's also donated to local Congressman Ted Lieu.
Lieu announced earlier this week that he plans to donate the more than $18,000 he's received from Buck to civil rights charities.