Authorities believe it may have started on I-45 and then eventually, the drivers moved to 610, where they fired shots at each other.
"(It's) unclear where he was shot, but it seems like they stopped on the freeway, shot at each other and then drove off," said HPD Det. Shawn Overstreet.
The driver in a Dodge was shot. He was taken to the hospital, where he died.
Police say they did find a weapon in his car.
The search for the second driver is ongoing. Authorities did not have a strong description of the second driver's car, only saying that it's a dark maroon sedan.
Officials say there were two witnesses who stopped to help.
If you have any information about the shooting, you're urged to call police.
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