Looks like a spirea of some type. I don't know about the spots, but if you tell us generally where you are as well as the plant's growing conditions such as amount of sun, type of soil and moisture, it may help others figure out the problem.

Spiraea has alternate foliage. This looks like Caryopteris to me. No idea what the problem is though.

Thanks for your reply. I'm in northern NJ. The plant gets afternoon sun. We've had a lot of rain this spring but the soil doesn't seem to be overly wet. I just turned on the sprinkler system this week.

I am almost certain the plant is Caryopteris and the marks are insect damage, probably from a four-lined plant bug. This is not a uncommon issue with caryopteris and you can find photos that look exactly like the OP's online.

Luckily, I've never needed to become familiar with 4 lined plant bugs;-)