Creepy mugshots of 1970s serial killer David Berkowitz (aka Son of Sam) hover over Jim Shalleck’s right shoulder in one of two new campaign ads the GOP candidate for Montgomery County Executive has posted on YouTube.

They’re a not-so-subtle reminder that the former Bronx prosecutor, who helped put Berkowitz away, is making public safety the centerpiece of his longshot campaign against incumbent Isiah Leggett in the November general election. Democrats have a 3-to-1 voter registration advantage in the county.

As he explained during candidate forums this winter and spring, Shalleck’s specific focus is school safety. He promises a constant police presence at every one of Montgomery’s more than 200 public schools.

“I never want to see a news helicopter over any one of them,” said Shalleck, who served in the Reagan-era Justice Department before entering private practice.

In the other 30-second TV spot, he assails county government spending, calling for an end to the nickel bag tax, a freeze on upcoming raises for County Council members and privatization of county-owned liquor stores.

Shalleck said the ads will run next month on Comcast cable and perhaps NewsChannel 8.