Arlington County’s police chief has acknowledged a pattern of internal memos dating back years that direct officers to make a minimum number of arrests and issue a certain number of traffic citations each month.

Chief M. Douglas Scott said that the memos did not amount to a quota system but that they could be interpreted that way. He has called quotas “professionally unsound” and has since directed his staff not to issue quotas or anything resembling them.

Scott was prompted to look at past memos to patrol staff after he rescinded a similar memo last month that threatened discipline for those who didn’t make enough arrests or write enough tickets. When he read older memos, he said, he learned that the practice was years old.

Scott is dealing with an issue that police chiefs across the nation grapple with as they work to give officers guidance without pushing them into arrests and ticket-writing.

He said he had not seen the memos before because he generally does not review memos that squad captains write to their officers. Had he seen them, he said, he would have stopped them.

“I was told we’ve always done it like this,” he said. “The commanders saw it as guidance.”

He has since directed his staff not to write such specific memos and instead to offer a general range for guidance. For example, he said that instead of directing officers to write 15 traffic tickets a month, he would recommend writing between 10 and 30.

“People understand ranges better,” he said. “Police officers are used to having some expectations of what their productivity should be.”

He added that he has never disciplined an officer for not meeting an expected number of arrests or tickets.

Scott said the numbers detailed in the March memo are “not difficult” to hit.

“The high majority of officers make those numbers easily,” he said.