On a part of the pastureland at the edges of the Washington metropolitan area, an uncommon and troubling event occurred last month, and authorities say they are still investigating.

A 1,300-pound black angus cow was killed, apparently with a crossbow, near Howsers Branch Road in the Aldie area of Loudoun County, according to county officials and the animal’s owner.

It was “extremely unusual,” said Chris Wolfe, who owned the pregnant 4-year-old beef cow.

“We have not had a situation, reported to us, where cattle have been randomly attacked and butchered on site” previously, said Chris Brosan, chief animal control officer for Loudoun’s animal services department.

The incident apparently occurred overnight from Dec. 21 to Dec. 22, the department said.

When found, the cow’s body was missing its right front leg, both back legs from the hips and a strip of back muscle, the animal services agency said.

The butchering skill that was demonstrated suggested that the meat was for sale rather than to satisfy hunger, Wolfe said.

So far, nobody is in custody, Brosan said Saturday. He said officials are waiting for forensic testing of the crossbow projectile retrieved from the slain cow.

Inevitably the incident may provoke thoughts of an earlier day, or crimes associated with the Old West. In the Loudoun incident, animal services said charges might include animal cruelty, trespassing and larceny.