When Jalapeno Peppers are fresh they usually have a nice shiny smooth surface to the skin of the pepper.
But as Jalapeno Peppers are going bad they start to become wrinkled on the outside.
But just because it's a bit wrinkled it doesn't mean the Jalapeno Pepper is bad yet but it just means that it's starting to become bad.
If the Jalapeno Is really wrinkled then it is likely bad but the bad Jalapeno may also feel a bit slimy on the outside or have a bad smell to it especially when you cut into the Jalapeno.
If the Jalapeno peppers are canned they will also start smelling bad or change texture and should be thrown out.
Best thing to do is to cut into the Jalapeno and smell it and if it smells bad then throw it out because it has spoiled.