According to a report from Houston television station Local 2, Reed had just withdrawn the amount from a bank and was headed to a Bank of America (presumably to move the money from one account to another.)
Authorities believe Reed was followed, which could certainly be the case if criminals were on the lookout for anyone walking out of a bank with that could possibly be carrying a large sum of money.
With technology allowing for wire transfers and money orders, perhaps it would be in Reed's best interest to not withdraw that much cash at one time in the future. But this isn't the time or place to point fingers, speculate or make judgments in hindsight. Regardless of what could have been done, no one deserves to be the victim of this kind of crime.
Hopefully, Houston police will be able to find the perpetrators and hold those accountable for the crime responsible for their actions.