Water Damage from Rain

[James Nix]

Hi Everyone,

Sorry for the blurry pics but this is pics of a 2nd floor unit bathroom of a duplex I own. Just wanted thoughts on what you think this could be?

Also should I call a roofer or plumber to handle this problem or just handyman? 

The bathroom has a sky light & it’s a 1950’s building so it has them old plaster walls.

Thanks in advance for any input