Called left no message hung up

Called my wife claiming to be collecting donations for some police organization.  She got the vibe something was off and said he tried to say that they were making calls because it's cheaper than mail.  I can't verify for certain but sounds like a scam to me.

Just got a call from a Mark about some police organization. Told him to mail me his literature and I would decide how much I would donate. He went out of his way to try to get me to say yes over the phone.

This is a cold caller claiming to be taking a pledge for police. In other words they want your hard earned money. They also want your number to be added to their sucker list they sell to others so they can get money too. Block them.