Без мотива следовательница вряд ли поверила бы в такую развязку.

Without a motive, the female investigator would hardly have believed such an ending.

Breakdown of Без мотива следовательница вряд ли поверила бы в такую развязку.

• в: in
• без: without
• такой: such
• бы: would

Questions & Answers about Без мотива следовательница вряд ли поверила бы в такую развязку.

Why is мотива in the genitive case?

Because без always governs the genitive in Russian.

• мотив = motive
• без мотива = without a motive

So this is not specific to this sentence; it is just the normal pattern:

• без сахара = without sugar
• без проблем = without problems
• без мотива = without a motive

What does вряд ли mean exactly?

Вряд ли means something like hardly, unlikely, or probably not.

In this sentence, it weakens the statement a little compared with a direct negation.

• не поверила бы = would not have believed
• вряд ли поверила бы = would hardly have believed / probably would not have believed

So вряд ли often adds a nuance of doubt or low probability rather than blunt refusal.

Why is it поверила бы? How is this conditional formed?