Charges of arson were levelled against Gust three days after a fire was ignited at about 2 a.m. Tuesday inside the restaurant at 2017 S. Washington St., causing about $90,000 in damages to the business. Other businesses in Juba's building also were affected

Court papers reveal police believe a molotov cocktail, in the form of a 40-ounce beer bottle containing gasoline, was thrown through the window of the restaurant.

Grand Forks Police Lt. Derik Zimmel said his department was not going to hazard any guesses on what the motive was before questioning Gust.

There has been widespread speculation that the arson attack was racially or religiously motivated, as it occurred just days after a Nazi-like symbol was spray-painted on the restaurant's exterior above the words "go home."

The Minnesota chapter of the Council on American-Islamic Relations released a statement shortly after news of the arson attack spread Tuesday, saying the incident fit a "pattern" of hate crimes targeting Muslims or people perceived to be Muslims in the aftermath of recent attacks in Paris for which Islamic State militants have claimed responsibility and killings in San Bernardino, Calif., which were perpetrated by a Muslim couple.

Police began zeroing in on Gust as a suspect after a Grand Forks resident told detectives he heard Gust had said something along the lines of "I blew up that place on the south end," according to court documents.

Evidence taken from the car Gust was driving the night of the attack and video taken from security cameras at Qdoba Mexican Grill in Grand Forks, where Gust worked, and a gas station further implicated him in the crime.

Police obtained video from cameras at an unnamed gas station that showed Gust paid $3 in cash for gas, but only pumped 81 cents worth of gas, or about 45 ounces, according to court papers.

The purchase was made 30 minutes before the attack on Juba restaurant, according to court documents.

Gust was captured on a camera at Qdoba being treated for "obvious injuries" to his right hand after the attack, which police said they believe he suffered in breaking the restaurant's window, according to court documents.

Zimmel, the police spokesman, declined to go into detail on the injuries Gust suffered.

A manager at Qdoba declined to speak to a Herald reporter about Gust.

Police found that the car Gust was driving that night belonged to his mother. Officers obtained her permission to search the vehicle, where they found what appeared to be blood stains and a full face mask, according to court documents.

The mask had a distinctive seam, court documents state, and appeared to match the one the arsonist captured in video from Juba Coffee House's cameras was wearing, according to court records.

Police also interviewed Gust's step-brother, who reportedly told officers Gust was known to drink 40-oz. Bud Light bottles, which would be the same kind of bottle police said they believe was used to make the molotov cocktail thrown into the restaurant, according to court documents.

The Herald earlier reported on police being called Tuesday morning to check on a man with a bloody right hand, but he was not connected to the arson.

Gust does not have a criminal record in Minnesota, but in 2012, he pleaded guilty to charges of terrorizing, simple assault and preventing arrest, all Class C felonies, in Grand Forks County District Court after he threatened staff at Romantix, an adult entertainment store in downtown Grand Forks, and assaulted a police officer in 2011. Officers used a Taser on Gust before taking him into custody then.

In the arson case, a court date will not be set for Gust until he is arrested.

Police asked the public to call the Grand Forks Police Department at (701) 787-8004(701) 787-8004 with any information on Gust's whereabouts. Tips may also be texted to 847411 with the word "Tipster."

A description of Gust was not released to media Friday night.