HOUSTON (KTRK) -- Houston police are looking for the killer or killers responsible for murdering two people in Midtown late Sunday night.The two people were found at 1100 Dennis Street near the Fannin Street intersection about 11:15pm.Leola Thompson says she was on the phone with her child moments before Robert Isaac, 34, was attacked."I can still hear his voice," Thompson said.Isaac was a transgender woman, known to friends as Shante."He said, 'I'll call you right back, I'll call you right back,'" Thompson said.But that call never came. Isaac was murdered and police are working to figure out why it happened. They are currently interviewing several witnesses.A man was killed too. His family identifies him as Willie Sims, 34, a friend of Isaac's. Initial reports from police say the two victims were shot. But investigators now say upon arrival, they found them suffering from multiple wounds, the exact nature of which are unknown at this time."The boy that was trying to protect my brother got shot, and my brother got hit in the head with something, like a crowbar from the car," said Jessica Thompson, Isaac's younger sister.When asked if this could be a hate crime, investigators couldn't say.Isaac's family is left wondering who would want her dead. They pray the person or persons responsible will be caught soon."I just want justice for my brother," Jessica Thompson said.Anyone with information on this case is urged to contact the HPD Homicide Division at 713-308-3600 or Crime Stoppers at 713-222-TIPS.