HOUSTON, Texas (KTRK) -- A person walking by spotted a homeless man and thought he was sleeping, until a closer look revealed the man had been a victim of a violent beating.The man was found along Travis Street, between Hadley and McGowen on Wednesday morning.The person who found him called 911. Police say the 50-year-old victim was taken to Ben Taub Hospital in critical condition, suffering severe head trauma."It looks like there was some kind of struggle and it looks like it was mainly (focused) towards his head," said HPD Det. Shaun Sylvester. "We are not sure if it was an instrument that was used at the same time or someone was trying to complete what they were doing. We're not sure."Police say no weapon has been found. An investigation is ongoing. They're hoping surveillance video from a nearby apartment complex may help shed some light on the crime.Anyone with information in this case is urged to contact the HPD Homicide Division at 713-308-3600 or Crime Stoppers at 713-222-TIPS.