An American arrested in Russia last week has been formally charged with espionage, Russian news agency Interfax reported on Thursday. If convicted on those charges, he could face up to 20 years in prison.

The latest update in the bizarre case of 48-year-old Paul Whelan comes nearly a week after his arrest in Moscow. Here’s what we know about him and his situation so far.

Who is Paul Whelan?

Whelan, a U.S. citizen, was born in Canada to British parents who moved his family to Michigan shortly after he was born, according to the Detroit Free Press. He has a twin brother, David Whelan, who has served as his family’s spokesperson.

He currently oversees global security for Michigan auto parts maker BorgWarner in Auburn Hills, Michigan, according to a statement released by the company on Tuesday. He also runs an online firearms business called Kingsmead Arsenal. Its address is listed as Whelan’s apartment in Novi, Michigan, public records show.

family handout Paul Whelan was discharged from the U.S. Marine Corps in 2008 following a special court-martial. He previously identified himself as a former sheriff deputy, which has been disputed by local authorities.

He testified in 2013 that from 1988 to 2000 he served as a police officer for the city of Chelsea, Michigan, and as a deputy for the Washtenaw County Sheriff’s Department. However, Washtenaw County Undersheriff Mark Ptaszek, reached by HuffPost on Thursday, said there is no record of Whelan having ever been employed there. The Chelsea Police Department and Whelan’s family did not immediately respond to requests for comment.

Records obtained by the Detroit Free Press show that he joined the Marine Reserves in 1994 and was deployed to Iraq in 2004 and 2006. He was convicted at a special court-martial in 2008 for attempted larceny, dereliction of duty, making a false official statement, using another person’s social security number, and making and uttering checks without sufficient funds. He was given a bad-conduct discharge.

In the years after his enlistment, he was employed by global staffing firm Kelly Services. In his 2013 testimony, he identified himself as a senior manager of global security and investigations for the company.

A spokesperson for the company, in a statement to HuffPost, confirmed his employment beginning in 2001 and said that “all relevant aspects of his employment application were appropriately verified.”

“Mr. Whelan remained an employee of Kelly Services until 2016, inclusive of his leave for military service. We have no information to suggest that Mr. Whelan ever traveled to Russia on Kelly business,” the statement read. “Out of respect for Mr. Whelan and his family, we have no further comment.”

family photo Whelan is a U.S. citizen but was born in Canada to British parents. His family moved to Michigan shortly after he and his twin brother were born.

What happened in Russia?

Whelan was arrested on Friday while allegedly conducting a “spy mission” in Moscow, according to a statement released on Monday by the Russian Federal Security Service, Russia’s security agency.

He was apprehended in his hotel room while allegedly meeting with a Russian citizen about obtaining classified information about staff members at various Russian agencies, the New York Times reported, citing a report by the Russian news agency Rosbalt. Whelan was reportedly handed a USB drive containing a list of employees at a classified security agency minutes before taken into custody. He is being held in solitary confinement in Moscow’s Lefortovo Prison.

Whelan’s family, in a statement posted to Twitter, has said that he was in Moscow to attend a fellow retired Marine’s wedding.

“His innocence is undoubted and we trust that his rights will be respected,” his family said.

Family handout Whelan was arrested on Friday while allegedly conducting a “spy mission” in Moscow, according to Russian authorities. His family denies that he is a spy.

What are Paul Whelan’s ties to Russia?

Whelan has previously traveled to Russia and has documented his trips on a personal website that is listed as last updated in 2009. He also has a personal profile on the Russian social media site Vkontakte. That profile is listed as last activated on Dec. 28, which is when he was arrested. Its status reads “Next stop, Moscow ... ”

According to the Times’ review of his connections on the site, most of his Vkontakte contacts are men with some kind of connection to academies run by the Russian Navy, the Ministry of Defense or the Civil Aviation Authority.

How has the U.S. responded?

U.S. Secretary of State Mike Pompeo said on Wednesday that he has asked for an explanation for Whelan’s detainment and that he will demand his release if an inappropriate response is given.

Whelan’s defense attorney Vladimir A. Zherebenkov told The Associated Press that he met with Whelan on Wednesday and found him in a “very hopeful” mood. He said he has also requested bail.

U.S. ambassador to Russia Jon Huntsman also visited Whelan in jail on Wednesday.

Rep. Haley Stevens, (D-Mich.), who took office on Thursday, said in a statement that she is committed to working with Whelan’s family to bring him home.

“Paul served our country as a Marine and law enforcement officer and we must ensure that Russia continues to meet its obligations under the Vienna Convention to provide U.S. officials access to Mr. Whelan,” she stated. “I am working with the State Department and will remain vigilant until Paul returns safely to his family in Michigan.”

ASSOCIATED PRESS Russian gun rights activist Maria Butina pleaded guilty to acting as a covert agent of the Russian government in December.

What is Paul Whelan’s connection to Maria Butina?

Some have suggested that Whelan’s arrest is in response to Russian gun rights activist Maria Butina pleading guilty last month to conspiring against the U.S. as an agent for the Kremlin. Butina, who has remained behind bars since July, has not yet been sentenced.

She faces up to five years in prison followed by deportation, though she is more likely to get zero to six months in prison under the terms of her plea deal that relies upon her cooperating with U.S. law enforcement.

Whelan’s attorney told the Times that he would be open to a prisoner swap, telling the paper: “I myself hope that we can rescue and bring home one Russian soul.”