There's "no other job where you get paid to tell the truth...we are detectives for the people." The late, great investigative reporter Wayne Barrett, in his last column for the Village Voice.
It is because “journalism is a discipline of verification,” that journalists consider the commitment to verification and accuracy a “strategic ritual” and part of their “professional identity,” which is “something that legitimizes a journalist’s social role as being demonstrably different from other communicators.” A devotion to accuracy is the value that journalists add to issues and stories in the information ecosystem. Barbara Gray, Newmark J-School, The Emerald Handbook of Modern Information Management, p 421
 Kovach, B., & Rosenstiel, T. (2014). The elements of journalism: what newspeople should know and the public should expect. New York: Three Rivers Press. 98.  Shapiro, I., Brin, C., Bédard-Brûlé, I., & Mychajlowycz, K. (2013). Verification as a Strategic Ritual: How journalists retrospectively describe processes for ensuring accuracy. Journalism Practice, 7(6), 657-673. 669.
Fact checking will bulletproof your reporting
Always ask yourself these questions when trying to verify information:
What Do I Check?
Where do I fact check?
Frequent Sources of Error
Source: Carroll, Brian. Writing and Editing for Digital Media. Routledge: 2014.
Make an Accuracy Checklist a part of your reporting process
Some other good checklists to use:
Fact-checking guides relating to politics:
"subconscious tendency to seek and interpret information and other evidence in ways that affirm our existing beliefs, ideas, expectations, and/or hypotheses. Therefore, confirmation bias is both affected by and feeds our implicit biases. It can be most entrenched around beliefs and ideas that we are strongly attached to or that provoke a strong emotional response." Source: Facing History and Ourselves
How to Thwart Your Confirmation Bias