Complete the dialogue with the missing modal verbs.

Choose the correct option.

Somebody has stolen jewelry at Laura’s party. Nobody has seen who did it. Lara's friends are making deductions about the theft.

Sam: It [need|must|should] have been the guy from pizza delivery! I’m absolutely sure it was him. He acted strangely, and he was wandering around the house for no reason. He [might|would|should] have taken the jewelry when everyone was having fun.

Angie: It [shouldn't|must|couldn't] have been the pizza guy. He left the house quite soon, and Lara showed us the jewelry after that. It [could|needn't|had] have been Christy; she seemed very jealous of the golden necklace.

Sam: I don’t think it’s possible. I spent a lot of time with Christy at the party; she [couldn't|shouldn't|won't] have done it without being noticed. And she’s got lots of nice jewelry herself, so she didn't [must|have to|had to] steal anything from her friend.

Angie: But what if you’re lying to protect your girlfriend?

Sam: You [should|won't|shouldn't] have said that! Oh, wait… And what about you? You saw the jewelry; you knew where it was; you definitely [can't|might|mustn't] have stolen the pieces!

Angie: Oh, no! I’d better go!