How to find out if your friend or a loved one is a serial kiler

Ask this question to someone:

One day you attend a funeral(Doesn't matter whose funeral). Then, you see the person of your dreams(technically, love in first sight). This person came with his/her brother, sister, and mother to the funeral. So it turns out that person is the daughter/son of the dead man. Now, the funeral is over and you didn't get any contact information from the person that you really liked and you didn't get to find out even her name. So the question is, what will you do so that you can get the his/her contact. (Assuming that you really like him/her that you would do anything just to get their contact info.)
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I will post tomorrow how you can find out if your friend or loved one is a serial killer.