"When I saw that on my caller ID, I pulled over," Castro said. "I didn't trust myself to be driving in the moment, and my stomach fell through, all the way down. My heart clenched. All I can think of is he's loose. He's on the streets in our community."
Castro's 17-year-old son was killed in a road rage shooting on July 6.
SEE ALSO: 17-year-old dies after being shot in the head while driving home from Astros game
Castro says he was driving his two sons back from an Astros game, when he and the driver of a white Buick exchanged hand gestures.
Gerald Wayne Williams, 34, is charged with murdering the teen after police say he followed the family onto I-10 and shot several times into their truck.
Williams posted $350,000 bond on Friday and is now out of jail while he awaits trial.
"The broken system allowed that man to make bond," Castro said.
According to records, Williams was convicted of two counts of aggravated robbery with a deadly weapon and served 12 years behind bars before being released in February 2020.
Prosecutors filed a motion to deny bond based on his previous record. On August 6, Judge Marc Brown set bond at $350,000.
SEE ALSO: Judge grants Gerald Williams bond in 17-year-old's road rage murder
Under the bail conditions, Williams is required to have electronic monitoring within two calendar days of his release. He must then remain under house arrest 24/7.
"He doesn't have an ankle monitor right now. He's on his own promise that he's going to stay in his home," Castro said. "He can be anywhere. I don't know how. But what I do know is a person, who has two armed robberies and is accused of killing my son, that person is out on the streets because our system isn't set up to protect us from him."
Castro believes with a simple policy change, authorities would've been able to monitor Williams as soon as he posted bond.
He now wants the community, who he says has embraced and supported his family, to help them take action and change how bail is set for some suspects.
"Every day has been a nightmare knowing my son is dead and sitting in a box," Castro said. "I feel it's my personal responsibility, and I am calling on the community to join me. We need to start on the county level. We need to be talking with Judge Hidalgo, our representatives, we need to be talking to everyone who represents the precincts. Posting on Facebook and Twitter is simply not enough."