The Lithuanian Security Police, also referred to as Saugumas (Lithuanian: Saugumo policija), was a Lithuanian Nazi collaborationist police force that operated from 1941 to 1944. It had a staff of approximately 400 people, 250 of them in Kaunas and around another 130 in Vilnius.
The police in Germany occupied Lithuania, and had consisted of separate Nazi German and Nazi Lithuanian units. The most important German police organizations were the security police (German: Sicherheitspolizei) and security service (German: Sicherheitsdienst) with their headquarters in Kaunas, and the public police (German: Schutzpolizei). The major Lithuanian police organisations were the Public Police, Lithuanian Security and Criminal Police, Lithuanian self-defence units (police battalions), Railway Police and the Fire Police. Lithuanian police organizations were subordinate to the respective German police organizations.  Motorized units of German police, Latvian, Estonian and Ukrainian police battalions were also present in Lithuania. In response to growing partisan activity in Eastern Lithuania, 9th and 16th regiment of SS police were sent there. 
The Lithuanian Provisional Government, a temporary government that was to govern Lithuania in the transitional period between the start of hostilities and the projected liberation of the country by Germany was restoring state institutions. On June 24, 1941, the authority recreated the pre-war Ministry of Internal Affairs and most of the men from the unit were accepted into its State Security Department headed by Vytautas Reivytis. There they were joined by many more former members of pre-war Lithuanian institutions, as the government asked all those working there prior to June 15, 1940, to report for duty. However, after the German take-over of Lithuania it became apparent that the Germans had no intention to grant autonomy to Lithuania and the government was dissolved on 5 August 1941. At the same time the police and intelligence agencies recreated during the transitional period were found useful and were incorporated into the German security system. The former Security Department was reorganised to Lithuanian Security Police. Many of its members came from the fascist Iron Wolf organisation.
Head of Lithuanian Security and Criminal Police was agent of Abwehr Stasys Čenkus. He kept this position until the end of German occupation. His deputy assistants were head of Security Police Kazys Matulis and personal secretary Vytenis Stasiškis. Head of Criminal Police was Petras Pamataitis.
LSP had six regional branches (Lithuanian: Apygarda) – in Kaunas itself (headed by Albinas Čiuoderis), in Vilnius (Aleksandras Lileikis), Šiauliai (Juozas Pakulis), Ukmergė (Aleksandras Braziukaitis), Marijampolė (Petras Banys) and Panevėžys (Antanas Liepa). The headquarters were divided onto several departments: Organization (head Povilas Žičkus, 1942), Economical and Financial (headed by Pranas Nenorta]), and Information (headed by Juozas Jucius). Melamed adds department of Communists, Ethnic Minorities and Jews to this list.
Regional branches usually had seven commissariats:
Regional branches sometimes had different set of commissariats, for example Kaunas's branch had commissariat for rightwing organizations.
Collaborating with the Nazi Sipo (Security Police) and SD, the unit was directly subordinate to the German Kripo (Criminal Police). As such, it fulfilled a variety of roles. Among its main tasks were providing the German police forces with information and intelligence on Polish resistance, Communist organizations and ethnic minorities. It also served the role of an anti-partisan unit in the area of German-occupied northern Poland and Lithuania. A special section within the Saugumas was devoted entirely to Jew Communists (Lithuanian: Komunistų-Žydų Skyrius). Finally, it presented its German superiors with proscription lists of Jews and intelligentsia bound for extermination, People suspected of Jewish roots, evaded being imprisoned in (or tried to escape from) the ghettos or those who violated the Nazi racial laws were arrested and handed over either to the Gestapo or to another Lithuanian collaborationist force named Ypatingasis būrys, which then transported them to the mass murder site of Paneriai or to other places of mass execution. Bubnys, however, claims, that Jewish questions were exceptionally in competence of German Security Police and German civilian administration. According to Bubnys, role of Lithuanian Security Police in extermination of Jews was minor and mostly limited to searching for individual Jews escaped from ghettos and transferring captives to the German Security Police. He points to the fact, that Lithuanian Security Police was directly subordinate to the German Criminal Police and not to the SD or Gestapo, which were directly persecuting enemies of Reich.
The activities of the LSP offices in major towns (Vilnius, Kaunas) and in the provinces differed in principle. The LSP officers in major towns would most often study more complicated cases of political and strategic character, thus not taking part in mass killing of the Jews directly. After interrogations, the arrested Jews would be forwarded to relevant police divisions which would perpetrate the mass slaughter.
Those LSP offices in the province took part in the Holocaust and, altogether, were more active. Here, the LSP officials would not only conduct the interrogations, but would also organize the very process of persecution of the Jews: mass arrests, transportation of the Jews to the venues of imprisonment and massacre. Heads of some LSP divisions in the province would also themselves supervise the massacre actions.
During the first months of German occupation, the Communist commissariat of the Vilnius branch, headed by Juozas Bagdonis, was especially active. This commissariat in some documents of 1941 is sometimes referred to as the Communist-Jewish section (Komunistų-žydų sekcija). This commissariat was responsible for spying on, arresting and interrogating communists, members of Komsomol, former Soviet government workers, NKVD collaborators, Jews and supporters of Jews. However, British historian David Cesarani contests this whitewashing of the Lithuanian collaborators who, like those collaborators of Latvia, Estonia, Ukraine, and other nations, actively assisted the nazis in mass-murdering the Jews and other victims within the territories occupied by the German troops. The Schuma, as the collaborationists were called, actively assisted the German authorities in annihilating the Jews of Lithuania.
There are known many cases of Lithuanian Security Police staff resisting the German occupiers. Staff participated in secret anti-Nazi organizations, distributed underground leaflets and secret information. For example, Povilas Žičkus, the head of Polital, later the Administrative Department of Security Police, was an active resistant to the German occupation and on 14 May 1944, was arrested by the Gestapo and deported to prison in Germany. Kazys Gimžauskas, deputy of commander of the Vilnius branch, was a member of the organization Kęstutis and illegally supplied information to the Lithuanian Front. Lileikis knew about the relations of his deputy with the Lithuanian underground but didn't tell anyone. In 1943, an employee of the Vilnius branch, Zenonas Pranckevičius, was caught distributing illegal papers and removed from service.
At the end of the war many members of the Lithuanian Security Police fled to Western Europe, notably to Germany. In 1955, the former commander of its Vilnius branch, Aleksandras Lileikis, emigrated to the USA, where he obtained citizenship, of which he was stripped in 1996. Lileikis's trial was postponed several times due to his poor health; he died at age 93 without trial. Kazys Gimžauskas, deputy of Lileikis, who returned to Lithuania after US authorities began to investigate him in 1996, was convicted in 2001 of participation in genocide. In 2006 Algimantas Dailidė was convicted in Lithuania of persecuting and arresting two Poles and 12 Jews while he was a member of Lithuanian Security Police.