Learn Polish: Przeszukawszy dom, policja zabezpieczyła ślady krwi. - Having searched the house, the police secured traces of blood.

Przeszukawszy is the adverbial anterior participle, meaning "having searched". It is formed from the perfective verb przeszukać. Because its past tense stem ends in a vowel (przeszuka-), we attach the suffix -wszy. This structure concisely shows that the search was fully completed before the main action (securing the evidence) began, replacing wordier phrases like po tym, jak policja przeszukała dom.

Is it possible that a different team searched the house, and then the police secured the traces?

No. A strict grammatical rule for these -wszy and -łszy participles is that the implied subject of the participle must be exactly the same as the subject of the main clause. Here, policja is the entity performing both actions. If a separate team searched the house and the police secured the evidence, you would have to use a standard subordinate clause instead of a participle.

Why is the verb "zabezpieczyła" in the singular feminine form?

In Polish, the noun policja is grammatically singular and feminine, regardless of how many officers are actually present. This is a common trap for English speakers who are used to treating "police" as a plural noun (e.g., "the police are"). Because the subject is a singular feminine noun, the past tense verb must match it as zabezpieczyła.

What is the difference between "szukać" and "przeszukać" in this context?