KALAMAZOO, MI -- Dr. Lukasz Niec, soon after dropping his stepdaughter off at the bus stop on a Tuesday morning, got a knock at the door that turned his life in a direction of uncertainty.

Three ICE agents stood on the front step of his home near Kalamazoo.

"I did not think this was happening," Niec, 43, said by phone Friday, Feb. 2. He was released on bond Thursday, Feb. 1, more than two weeks after he was arrested and jailed.

When the agents put handcuffs on him and put him into a vehicle for transport, Niec realized it wasn't a joke. They asked for his Green Card and passport and put him in the back of a car, he said.

The agents said they were there because of two misdemeanor convictions from 1992, Niece said, though one was wiped from his record because he completed probation under Holmes Youthful Trainee Act, which allows young offenders to have convictions taken off their records.

He believes a tip prompted ICE to investigate him.

"The inclination is that there was a call made into the tip line," he said. "Then they started looking in deeper and deeper.

"That's why they came for me," he said.

When asked if he believes the tip was from his ex fiancee who is involved in a legal battle with Niec over child custody, Niec said, "I can't think of anyone else."

"I don't know for sure," he said. "More things are coming up that point to that person."

The custody battle includes allegations of child abuse against Niece, which he previously denied in court testimony and denied again on Friday.

ICE has not responded to questions about whether or not a tip was sent to the agency.

ICE officials have said that the agency began an investigation of Niec because of child abuse allegations against him.

Niec has taken care of immigration detainees in his job as a doctor at Bronson HealthCare, but he said he doesn't know much about how the immigration agency works.

He is a citizen of Poland and came to the United States with his family at age 5.

ICE said he came to the U.S. legally and he is amenable to removal proceedings as a result of two 1992 state convictions for malicious destruction of property and receiving stolen property, both of which are crimes involving "moral turpitude," ICE said.

In the destruction of property case, Niec said he did not do anything wrong, but was guilty by association. In the receiving stolen property case, he said friends used a card to get money, and some of it was given to him.

He completed probation after the stolen property case and believed it would be wiped from his record.

"Everybody can make mistakes when they were young," he said. "Obviously I turned my life around I feel like. I didn't continue that kind of behavior."

Niec most recently came under agency scrutiny as a result of 18 encounters with local law enforcement, ICE said. The agency did not provide further specifics of the encounters.

Kalamazoo County District Court records show Niec has 22 cases generated from 18 contacts with police. Violations include four no proof of insurance violations, seven speeding tickets, failure to change address on license, causing an accident, careless driving, seat belt violation, driving without due care, and parking near a fire hydrant.

Niec pleaded guilty to a 2008 operating impaired by liquor offense in Kalamazoo County. He completed probation, and the conviction was set aside, the plea withdrawn and the case dismissed, as part of a plea agreement.

He was charged with domestic violence in 2013 and a jury found him not guilty after a trial, record show.

After the arrest by ICE, Niec said he absolutely wants to obtain citizenship.

"I had no clue, I thought having a permanent Green Card was very similar to having citizenship," he said."Obviously I wish I had done it earlier because I wouldn't be in this predicament."

Hindsight is easy, he said.

"I wish I did it, I got busy, just too many things," he said when asked about obtaining citizenship. "I was married, and medical school, both my parents passed away and everything just got delayed and delayed between college and just trying to move forward with my life."

He put it on the "back burner," he said, thinking there was no reasonable likelihood he would be in the situation he is in now.

He doesn't know the odds of deportation.

"I absolutely want to stay," he said.

His employer, Bronson HealthCare, has been supportive, he said, and he can go back whenever he is willing to, likely next week, he said. He thanked all of his supporters.

He's felt upset, shocked and frustrated since his arrest, but he said he's trying to make the best of it. He was happy Friday night to be with his family and friends.

"I've obviously realized I just have to go through it," he said about the immigration proceedings.

He doesn't blame ICE for enforcing the laws, but he believes the laws could be given another look.