After splashes of green paint shut down the Lincoln Memorial for several days this week, the city’s representative in Congress has an explanation: the sequester.

Rep. Eleanor Holmes Norton, D-D.C., penned a letter to the National Park Service warning that more monuments could be at risk of vandalism because of lighter patrolling since the $1 trillion spending cuts hit March 1.

“There is now considerable concern about whether other monuments on the National Mall are in jeopardy of being vandalized, and whether there is adequate protection to ensure that such acts do not occur in the future,” Norton wrote.

She demanded an investigation into the vandalism, which was reported at the Lincoln Memorial and the National Cathedral this week. City police arrested a suspect, a woman who is apparently homeless, earlier this week.

More than $150 million was slashed this year from the National Park Service budget, which also faced a hiring freeze last month that left 900 positions vacant.

Norton said the city needed to coordinate patrols across its many parks and museums – from the Capitol Police to the National Zoological Park Police – to prevent future damage.

“No matter how many police forces are in the nation’s capital, we will not be able to meet the challenges we face today to protect against the unexpected unless there is coordination among the police forces,” she wrote.