MILWAUKEE (AP) ― Violin virtuoso Frank Almond was walking to his car after an evening performance at the Wisconsin Lutheran College when someone jumped out of a van, shocked him with a stun gun and seized the rare and extremely valuable Stradivarius on loan to him.

The robber got back into the waiting vehicle, which sped off.

Almond, who had been knocked to the ground, wasn’t seriously hurt. But he was devastated by the loss of the violin, which was crafted in 1715 and has been appraised for insurance purposes at $5 million.

The brazen Jan. 27 crime set off a frantic search and raised questions about why someone would steal an item that would be nearly impossible to sell. Would-be buyers in the tiny market for rare violins would certainly know it was stolen, and keeping it in hiding would mean never getting to show it off.

The case in which Almond kept the instrument was found, and the Milwaukee Symphony Orchestra announced someone was offering $100,000 for the instrument’s safe return. But there weren’t any breaks in the robbery until this week, when prosecutors confirmed Wednesday that three people had been arrested in connection with the theft.

However, Police Chief Ed Flynn said at an afternoon news conference that authorities haven’t recovered the violin, and he hoped the reward would induce the public to come forward with tips.

“It’s a reasonable supposition that it’s still in our jurisdiction,” Flynn said. He declined to go into detail.

Kent Lovern, a Milwaukee County assistant district attorney, said he didn’t expect a charging decision would be made before Thursday.

Flynn said the suspects were two men, ages 41 and 36, and a 32-year-old woman. He wouldn’t say how police tracked them down, but he said there was physical evidence linking them to the crime.

Flynn also wouldn’t speculate on a motive, although he said the suspects seemed to be working for themselves, not on behalf of a larger art-theft ring. He also said one had a previous association with art crime.

The violin is known in musical circles as the “Lipinski” Stradivarius. Its previous owners include virtuoso Giuseppe Tartini, who was known for his “Devil’s Trill” Sonata, and Polish violinist Karol Lipinski.

It was passed down through generations, eventually landing with the heirs of Estonian violinist Evi Liivak, according to Stefan Hersh a Chicago-based violin curator who helped restore it to playing condition after it was removed from storage in a bank vault in 2008. The current owner’s name has not been revealed publicly.

Hersh, a friend of Almond’s, said he used to watch how carefully Almond would care for the violin. While some musicians see their instruments as objects or tools, Almond understood the historical significance of the Lipinski, Hersh said.

“He had a special case made for it, he kept it highly protected in his car, he never let it out of his sight,” Hersh said. “As a performer nothing shakes him, but after the theft he was highly shaken. I’ve never known him like that.”

A message left for Almond through the Milwaukee Symphony Orchestra wasn’t immediately returned Wednesday. Police have asked that he not speak to the media while the investigation was going on.

Hersh said Almond had scars on his wrist and chest from the stun gun but otherwise wasn’t seriously hurt.

Hersh said he couldn’t sleep after he heard about the theft. He was worried the violin would be damaged, but the more he thought about it the more he suspected the thieves would take pains to protect their spoils.