MILWAUKEE — A 300-year-old "priceless" Stradivarius violin was stolen from the Milwaukee Symphony Orchestra's concertmaster during an armed robbery after a performance at a local Lutheran college, police said Tuesday.

The rare violin was on loan to concertmaster Frank Almond. The robber used a stun gun on Almond and took the instrument from him shortly before 10:30 p.m. Monday in a parking lot in the rear of Wisconsin Lutheran College, where Almond had just preformed, Milwaukee Police Chief Edward Flynn said.

Flynn said the violin was valued in the "high seven figures," the Milwaukee Journal Sentinel reported. Investigators believe the instrument, known in musical circles as the "Lipinski" Stradivarius, was the primary target, the chief said.

"The artistic heritage of Milwaukee was assaulted and robbed last night," Flynn told reporters.

As Almond lay on the pavement, the robber fled to a nearby vehicle, described as a maroon or burgundy minivan driven by an accomplice, which then left the scene, Flynn said.

In a 2008 Journal Sentinel story, Chicago violin dealer Stefan Hersh said the violin's value could be comparable to another Stradivarius that sold for more than $3.5 million in 2006.

The instrument, crafted in 1715, was on indefinite loan to Almond from its anonymous owners. Almond has characterized the owners as people with "strong ties to Milwaukee."

The violin's previous owners include virtuoso Giuseppe Tartini, who was known for his "Devil's Trill" Sonata, and Polish violinist Karol Lipinski.

In a 2013 interview, Almond explained that the Lipinski is "finicky" about temperature and humidity, responding differently some days than others.

Almond conducted an online campaign to fund "A Violin's Life," a recording that memorialized the history of the violin.