。
The suspect lied to the investigator.
Literal
Suspect [topic-は] investigator [to-に] lie [object-を] said.
嘘を言う ('tell a lie') is a standard collocation — 嘘をつく is equally common. 捜査官 ('investigator / detective,' formal) contrasts with 刑事 ('detective,' casual). The に marks the recipient of the lie.