Speaking at the first Judiciary Committee hearing on immigration reform yesterday, Senator Chuck Grassley tied his concerns about the issue to the bombings in Boston this week, which were allegedly carried out by immigrants who had lived in the United States for years.

'Given the events of this week, it’s important for us to understand the gaps and loopholes in our immigration system,' he said. 'While we don’t yet know the immigration status of the people who have terrorized the communities in Massachusetts, when we find out, it will help shed light on the weaknesses of our system.'

'How can individuals evade authorities and plan such attacks on our soil?' Grassley continued. 'How can we beef up security checks on people who wish to enter the US? How do we ensure that people who wish to do us harm are not eligible for benefits under the immigration laws, including this new bill before us?'

According to the Huffington Post, the hearing was rocked by the events in Boston and by news that police had been caught in a gun fight with Dzhokhar Tsarnaev, 19, and Tamerlan Tsarnaev, 26, the brothers who were identified Thursday as the chief suspects in the bombing at the Boston Marathon.

Tamerlan Tsarnaev was reportedly killed in the firefight but his younger brother is still was still on the run. It is not yet know which types of visas the two young men came to America with but it understood that both men entered the country legally. Dzhokhar Tsarnaev reportedly became a citizen on September 11 of last year, while Tamerlan Tsarnaev became a legal permanent resident in 2007, the Post reported.

Some Republicans saw an opportunity to halt progress on reform and argued that plans to legalize undocumented immigrants should be delayed by the events. Speaking earlier in week Congressman Steve King, a well known opponent of immigration reform, expressed his concerns: 'Some of the speculation that has come out is that, yes, it was a foreign national and, speculating here, that it was potentially a person on a student visa,' King told the National Review's Robert Costa. 'If that's the case, then we need to take a look at the big picture.'

But Democratic Senator Chuck Schumer, a member of the so-called gang of eight that drafted the reform legislation released this week, rebuked his Republican colleagues for tying the Boston bombings to the bill.

Schumer said he will work with the Department of Homeland Security to ensure efforts to strengthen the visa screening system, but reminded fellow senators that it's still unclear it would have helped in this case.

'I'd like to ask that all of us not jump to conclusions regarding events in Boston or conflate those events with this legislation,' Schumer said. 'In general, we're a safer country when law enforcement knows who is here, has their fingerprints, photos, etcetera, conducted background checks... Two days ago, as you may recall, there was widespread erroneous reports of arrests being made. This just emphasizes how important it is to allow the actual facts to come out before jumping to any conclusions.'

Schumer was referring to a New York Post story, after the newspaper was accused of jumping to conclusions when it ran a front page photo on Thursday of two men it said authorities were seeking after the Boston Marathon bombing. By afternoon it reported that they had been cleared, the FBI was not searching for them. On Monday the Post also reported that authorities had questioned a Saudi man, who was also later cleared of any involvement. The Post came in for further criticism when it reported that many more people had died in the attacks than turned out to be true.

Yesterday Senate Judiciary Committee Chairman Patrick Leahy also said that he does not believe the Boston bombing should affect the push for comprehensive immigration reform, nor should it.

'If we change the policies in this country every time something happens - whether it's Oklahoma City, 9/11, this - then we're never going to do anything,' he told reporters. 'We should think about where the best policies are for the United States and use those.'

Meanwhile Gang of eight members John McCain and Lindsey Graham issued a joint statement on Friday afternoon saying they believed their reform bill would boost national security:

'In the wake of this week’s terrorist attack in Boston, some have already suggested that the circumstances of this terrible tragedy are justification for delaying or stopping entirely the effort for comprehensive immigration reform. In fact the opposite is true: Immigration reform will strengthen our nation’s security by helping us identify exactly who has entered our country and who has left -- a basic function of government that our broken immigration system is incapable of accomplishing today.

The status quo is unacceptable. We have 11 million people living in the shadows, which leaves this nation vulnerable to a myriad of threats. That is all the more reason why comprehensive immigration reform is so essential. By modernizing our system of legal immigration, identifying and conducting background checks on people here illegally, and finally securing our border, we will make America more secure.'

Dzhokhar Tsarnaev, 19, and Tamerlan Tsarnaev, 26, the brothers from Chechnya who were identified as the chief suspects in the bombing at the Boston Marathon.