The main perpetrators were detachments of the Einsatzgruppen, the Sicherheitsdienst (SD), the Ordnungspolizei (ORPO), and Latvian auxiliary police and militia forces.

[1] In addition to Jewish men, women and children (c. 5,000), the Germans and their Latvian collaborators also killed Roma (c.100), communists, the mentally ill[1] (c. 30) and so-called "hostages".

The largest massacre, of 2,731 Jews and 23 communists, occurred in the dunes surrounding the town of Šķēde, north of the city center.

For example, at 5:00 p.m. on June 29, arriving German soldiers seized 7 Jews and 22 Latvians and shot them at a bomb crater in the middle of Ulicha street.

[10] One of the first people EK 1a killed, on June 30, was the musician Aron Fränkel, who, not knowing that Einsatzkommando had set up headquarters at his place of employment, the Hotel St. Petersburg, showed up for work.

On July 3 and 4, 1941, in their first documented massacre in Liepāja,[8] Reichert's EK 1a men, all Germans of the SD, rounded up Jews and marched them to these trenches in the park.

[11] After the war, the Soviet Union investigatory commission concluded that 1,430 people were killed in the park shootings, which Ezergailis characterizes as an exaggeration.

[12] Summarized these were as follows:[14] On July 3 or 4, Erhard Grauel, commander of a detachment of Einsatzkommando 2, entered the city with about 30 men, most of them from Police Battalion 9 of the Ordnungspolizei.

[15] The numbers killed in the hostage massacre were stated as 30 in Grauel's postwar trial, and estimated at 27 plus or minus 16 by Anders and Dubrovskis.

[8] On or about July 7, 1941, Reichert returned to Liepāja, with a message from Franz Walter Stahlecker, commander of Einsatzgruppe A, that accused Grauel of not executing people fast enough.

The procedure was for the Latvian "freedom fighters" (as they were called by Hartman) to drive the victims ten at a time into a long ditch that ended in a pit.

His request was granted by the Einsatzkommando 2 commander, Rudolf Batz, and by the end of October, Grauel returned to Germany to study jurisprudence.

Historian Ezergailis noted however, that before returning to Germany, and despite his claim to have been shocked by the July 8–10 massacres, Grauel went on from Liepāja to the nearby town of Ventspils, where he organized additional killings.

27 July 1941: "Jewish problem Libau largely solved by execution of about 1,100 male Jews by Riga SS commando on 24 and 25.7."

[8] Otto Fischer, Jewish football coach and former Austrian national team player, was killed in the massacres in July.

[20] On July 22, Kawelmacher sent a telegram to the German Navy's Baltic Command in Kiel, which stated that he wanted 100 SS and fifty Schutzpolizei ("protective police") men sent to Liepāja for "quick implementation Jewish problem".

[22] A few days later, on Saturday, July 24, 1941, Rosenstock saw Jews (whom he identified by the yellow stars on their clothing) crouching down in the back of a truck, being guarded by armed Latvians.

Rosenstock, who was himself in a vehicle, followed the truck to the north of the city to the beach near the naval base, where he saw Kügler, some SD men, and a number of Jews.

[25][26] On December 4, 1941, Hinrich Lohse issued a decree[27] which stated: Gypsies who wander about in the countryside represent a two-fold danger.

[26] By May 18, 1942, the German police and SS commander in Liepāja indicated in a log that over a previous unspecified period, 174 Roma had been killed by shooting.

[29] The Latvian police began arresting the Jews in the city on the night of December 13 to 14, bringing them to the Women's Prison, where they were confined in the courtyard.

[29] Pēteris Galiņš, of whom little is known other than that he was killed in Russia in winter 1943,[30] was in charge of the Latvian guards, and he ordered a team of 20 to report for duty at 5:30 a.m. on December 15.

[29] Once at the site, the Jews were housed in the barn and taken in groups of 20 of a time to a point 40 or 50 meters from the trench, where they were ordered to lie face down on the ground.

A Latvian guard, Bulvāns, later testified that he saw two Germans, SS-Scharführer[32] ("squad leader") Karl-Emil Strott[33] and Philip (or Filip) Krapp, using a whip on people who did not move on to the pit.

After the initial volley, a German SD man would step down into trench, inspect the bodies, and fire finishing shots into anyone left alive.

[36] He saw a column of 300 to 500 Jews of all ages, men and women, being led under guard past his unit's headquarter's north on the road to Ventspils.

Lucan did not see the actual shooting, but he and other members of his unit heard rifle fire coming from the direction of the pit for a long time.

[40] For example, a boatman who worked under the harbormaster, Navy personnel and at least one hundred Heer soldiers were present at an execution, apparently pursuant to orders.

After the Germans were driven out of Latvia, Zivcon retrieved the prints, which were later used in war crimes trials and displayed in museums around the world.

Following the December shootings, the executioners repeatedly returned to the beach at Šķēde for killings, extending the trench along the dunes until it reportedly reached a length of one kilometer.