Authorities say David Reyes got into an argument with mechanic Sam Rivera while Rivera was working.
They say Reyes pulled out a gun and shot Rivera, who later died at the hospital.
Reyes hasn't been seen since.
His family spoke with Action News Friday.
"We believe in our brother's innocence for one, and we feel that he should turn himself in so that we can handle these things the right way according to the law, and to be tried by a judge and jury and not by anyone else," said the suspect's sister.
There is a $20,000 reward for tips leading to David Reyes.
