に着手

begin work on

→ に
phrase Rare #42,334
begin work on Used after a project, task, investigation, or other undertaking to mean starting work on it. Commonly used as に着手する; it is somewhat formal.
JA: 市は新しい橋の建設に着手した。
EN: The city began work on the construction of a new bridge.

警察はその犯罪の解決に着手した

The police began working to solve the crime.