Ezergailis gives an overview of the Order Police in Latvia as follows:
Before the Aråjs commando was trained, it was the 9th Battalion of the Ordnungspolizei that performed most of the killings for Stahlecker. The 9th Battalion units that were in Latvia during July and August had moved on, following Stahlecker to the environs of Leningrad. At the end of November there were at least two kinds of Ordnungspolizei units in Rîga under the command of Lieutenant Colonel Flick: the Schutzpolizei, headed by Major Heise, and the Gendarmerie, under Captain Rehberg. At least several hundred were posted to assure order (“obtain and maintain a German character”) in Rîga, as in Latvia at large. In addition to overseeing the Latvian precinct police, the Ordnungspolizei was also in charge of the ghettoization of Jews, and after October 25 the guarding of the ghetto. During the initial phase of the ghetto the SD were not involved. The Ordnungspolizei's involvement with the ghetto also predetermined their assignments in the liquidation of the ghetto.A West German trial of Order Police defendants included a description of Jeckeln's organization of the Rumbula action, provided by the defendant Friedrich Jahnke. Ezergailis also discusses the strong Latvian presence at Rumbula, including the planning meeting:
The 2nd company of the 22nd Reserve Battalion from Rîga supplied about seventy men, and the 3rd company of the 22nd Reserve Battalion from Jelgava supplied another seventy men. The 2nd company was employed in overseeing the clearing of the Jewish apartments, organizing the Jews into marching columns, and accompanying the columns to Rumbula. The 3rd company was used to guard of the periphery at Rumbula. The chief Ordnungspolizei activist was Major Heise, and it appears that he was also the liaison person with the Latvian Schutzmannschaften.
In addition to the 22nd Battalion from Rîga and Jelgava and the men of the Gendarmerie, Jeckeln had at his disposal another five regiments of Ordnungspolizei, but we do not know which, if any, of them he used. In general, Jeckeln was against involving the Wehrmacht.
Various German witnesses mention the presence of Latvian officers in the preparatory meeting. Although the only name mentioned is that of Osis, the head of the Latvian Schutzmannschaften, the names of the other Latvians present at these meetings can easily be identified, for the choice is a very narrow one. The only ones who could have been there in addition to Osis, were Aråjs, Ítiglics, and the head of the Latvian ghetto guard, Danskops.At Liepaja, there an initial killing action in July 1941. A notable feature of this action is that it was ordered by a naval commander, Kawelmacher, as Ezergailis again describes:
The pace of shootings was not fast enough for commandant Kawelmacher (a.k.a. Gontard). On July 22 he telexed the commanding admiral of the Baltic fleet in Kiel, requesting 100 SS- and 50 Schutzpolizei troops “for rapid execution [of the] Jewish problem. With present SS-personnel, this would take one year, which is untenable for [the] pacification of Liepāja.” His request was promptly granted; the notorious Latvian SD Commando under Viktors Arājs arrived from Riga, shot about 1,100 Jewish men on July 24 and 25, and left. Meanwhile the 2nd Company of Police Battalion 13 under SSHauptsturmführer Georg Rosenstock had arrived, primarily for patrol duty and to a lesser extent for executions. From then on, the Navy played a less active role, leaving the persecution of Jews in the hands of Kügler and his superior, SS-und Polizeistandortführer Dr. Fritz Dietrich, who arrived in mid-September.As was noted in this blog, Dietrich's arrival was crucial because he kept a diary of subsequent events. The main December massacre was ordered by HSSPF Jeckeln, carried through by Dietrich, and photographed by Strott and Sobeck, as Ezergailis describes:
No ghetto had yet been established in Liepāja, but Dietrich ordered a 2-day curfew for Jews. Thus confined to their apartments, they were methodically rounded up by Latvian police and taken to the Women’s Prison. From there they were marched to the Šķēde execution site, ordered to undress, and were shot in groups of 10 by three firing squads, two Latvian and one German. All together, 2,749 Jews were shot on December 15–17. They were mainly women and children, who had been largely spared until now. Kügler’s deputy SS-Scharführer Carl Emil Strott, as well as SSOberscharführer Sobeck, photographed the executions. An audacious Jew working at the Security Police, David Zivcon, got hold of a 12-exposure film by Sobeck long enough to make copies, which have been widely reproduced and exhibited after the war.Several of Strott's photographs, linked by Roberto here, and also discussed here, clearly show Latvian police taking women and children to the killing area. Strott's trial, at which he did not deny the photos, is here.
For Ponary, an excellent gallery of photographs can be found here. Three larger-sized examples from that gallery are shown here and here and here. Details in the photos match eyewitness testimony given to West German prosecutors that is reproduced here. See for example the book-keeper's statement that "The other nine walked one behind the other, stooping and holding on to the man in front with their hands because they could not see." Finally, note again that this massacre was not carried out by a unit of Einsatzgruppen acting alone. Lithuanian collaborators played an essential role in this murder.