Walter Bolt was an officer in a N.Y.P.D. drug task force. One day, he and his partner were undercover performing what they thought would be routine surveillance of a meeting. The meet went bad, and violence broke out. Punisher intervened, stopping Bolt from doing something stupid and wisely pulling the alarm to get civilians clear before the shooting began.
When the firefight broke out, Bolt froze but Punisher used his weapon to put down the gang, but it did not save Bolt's partner. After the debriefing, Bolt took the credit for saving the bystanders and the expert shooting, but what the NYPD didn't know was that he had since that day become an informant for the vigilante
Walter Bolt was created by Greg Rucka and Marco Checchetto in the first issue of their 2011 Punisher series.
In the establishing scenes of late 2011's Punisher series, by Rucka and Checchetto, Bolt is being investigated for the incident that led to the death of his partner. He is commended for his quick thinking and action but what he doesn't tell them is that Punisher was the man behind the heroics.
When he is teamed up with Detective Ozzy Clemons on the case of the Wedding Day Massacre that saw the hospitalisation of former Marine Rachel Alves and the murder of her husband and all of their families and friends at the hands of crime organisation The Exchange, he immediately sets about providing intel on the group to the Punisher.
Much to his dismay, he discovers that Detective Clemons is aware of his connection with the Punisher, as Clemons has been on the Punisher case for a very long time and Bolt has set about trying to hide his own predicament from the detective. Regardless, Bolt cannot stop and eventually is forced to admit that Punisher saved the day all those months back, for which he is actually respected more by his peers, to Clemons' dismay.
When Punisher and Rachel Alves assault the Exchange HQ, Bolt arrives on the scene during the fight and is accidentally shot dead by Alves!