A man was shot and killed inside his brother's home Saturday.
Police have not determined when the shooting took place, but it happened in the 600 block of Rigsby Avenue on the city's east side.
The dead man has been identified as 41 year-old Noe Hernandez.
He had recently moved in with his brother and was home alone.
According to police, just before 6:00 p.m., the victim's brother called his wife and the victim's sister-in-law, and asked her to go check on the man.
Police said the victim was going through some personal problems.
When the victim's sister-in-law arrived she tried to open the front door, but it was blocked. She looked down and saw a body.
"She calls police in a frantic state of condition, as you can imagine, saying there's broken glass and a man lying in my living room," said Sergeant Gary Pelfrey with the San Antonio Police Department.
When officers arrived, they found Hernandez lying near the doorway. Police said he was shot once in the shoulder. There were no signs of forced entry into the home.
"I think whoever did this opened that first primary door and then shot through the frame door," said Pelfrey.
Investigators have not ruled out that this could be a random act of violence, but they believe the shooter and victim may have known each other.
"He answered the door in a manner that someone knew who it was or they made an assumption and they fired," said Pelfrey.
Police spent several hours scouring the neighborhood for witnesses, but as of Saturday night they had no suspects.