'without investigating' is correct and usable in written English.
You can use this phrase when you are talking about a particular action that is not being done or has not been done. For example, "The police were unable to solve the case without investigating further."
Why aren't they challenging the BBC's reporting, which follows the tabloid frenzy without investigating tabloid behaviour?
"They can't investigate the Waters case without investigating mine," Mr. Rangel said.
As such, I tend to let a lot of world music trends pass me by without investigating them.
But Democrats said the illuminating fact was that the governor, without investigating first, questioned a critic's integrity.
However, the way that such data are coded into characters for phylogenetic analysis has been approached in different ways, without investigating how coding methods may affect the results.
The United States recently has tried to elevate cooperation with the Chinese police to fight international drug trafficking, making it difficult to dismiss Beijing's allegations without investigating them.
Mayor Chris Coleman said in an interview last week that the two former prosecutors looking into the incidents would conduct a broad overview without investigating specific complaints.
So far, he has insisted on trying to recalibrate the agency's policies without investigating past mistakes or holding anyone responsible for them.
Why did a regulated UK investment firm entrust the nesteggs of thousands of mainly retired people to a less-than blue-chip firm without investigating those behind it?
Mexicans want a full accounting of who benefited from the loans that bankers made to their friends without investigating the ventures' viability.
"Do we know of any country in history that let a foreign spy vehicle land on its territory without investigating?" asked Mr. Yan of Qinghua University.
