Our sister station, KTRK-TV, learned homicide detectives asked some of those close to the case not to talk about it publicly as they launch a probe into Sharkey's life and death.
KTRK has also learned investigators are looking into Sharkey's marriage as part of their efforts to determine what happened to the 26-year-old known for her Instagram presence.
Her husband, Tom Sharkey, told reporter Steve Campion, Alexis was his life partner. He described the marriage as happy and solid. Friends close to her dispute that account.
They told KTRK the marriage was on the rocks and in trouble.
Timeline: What happened before Alexis Sharkey's death
Timeline: What happened before Alexis Sharkey's death
We've learned the couple lived at an apartment complex in Houston's Energy Corridor. Investigators found Sharkey's body about three miles down on a feeder road.
KTRK spoke with three friends close to Sharkey who simply called her "Lex or Lexi." Lauren Breaux, Ally Cale, and Courtney Ehninger said their friend feared for her life and was worried about her safety in the weeks leading up to her disappearance.
WATCH: What happened to Alexis Sharkey?
What happened to Alexis Sharkey?
"We don't know what happened. We obviously have had ideas. We believe she was murdered, absolutely," said Breaux. "I'm going to be honest, she confided in me about how worried she was for her safety when we went to Marfa, Texas almost a month ago. We were sitting down at dinner and she lost it. We walked back to our hotel room and she confided in me that night in things. I looked at her [and thought], 'She's petrified. This girl is scared for her life.'"
When asked who Alexis was worried about, they remained silent. The friends did not want to disclose who Alexis feared in her life because they did not want to jeopardize the homicide investigation.
RELATED: Alexis Sharkey's husband says he's receiving death threats
Alexis Sharkey's husband says he's receiving death threats