I'm thinking there's going to be some sort of reference in Krekel's newspaper, the St. Charles Demokrat. Which was Krekel's own newspaper.
I've found a pretty lengthy report of the Givens Farm fight which ran in the Demokrat and was reprinted in the Westliche Post on 9/13/1862. All in German.
To my surprise, I'm having a bit of success translating some of these myself. Krekel's official report which showed up in the O.R. was just a few sentences long. Brief, uninformative and lacking in detail. The Givens Farm affair report he ran in his own newspaper was about a dozen paragraphs. More detail. It's not real accurate from what we know in looking at the bigger picture -- But....if he ran the Givens Farm matter in the Demokrat, he may have run other heavily sanitized reports on his other misdeeds such as killing Brewer et al.
Regarding the Demokrat's article on the Givens fight, of course Krekel didn't say his men captured civilians and then shot them down in cold blood but he, on the pages of the Demokrat, does talk about a guerrilla gang under "Capt. Davis" paying a visit to Fulton right before Krekel was stationed there. Davis' band raided the courthouse and stole the books. Davis took a Negro locked up for attempted murder from the jail and were about to shoot him when they were apparently dissuaded from killing him (having trouble working out this part). Wonder who Davis was.
The article goes on to talk about how Krekel's force of four cavalry companies and one infantry company arrived after the Davis raid on Fulton. "All of Callaway is teeming with bushwhackers and every effort is needed to eradicate the bands distributed in all parts of the county," says the Demokrat report, translated. Krekel installed his troops in the "infirmary" (hospital?) "and dumb asylum" (insane asylum) because it was feared a camp in an open field would be too exposed.
Article says last Friday Krekel sent Capt. Windmuller with 50 cavalrymen about 7 miles from Fulton and found a guerrilla camp of 200 men. Windmuller ordered an attack and fought the bushwhackers until his men ran out of ammunition and was at risk of being surrounded by the superior rebel force.
Windmuller killed 15 rebels, seven of whom were shot during the retreat. Windmuller had one man shot in the leg, another in the chest, but not seriously injured.
Gen. Merrill offered five companies to help Krekel.
Gen. Guitar was said to have penetrated Callaway with a force from Jefferson City.