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Judge Maureen S. O'Sullivan
FY 2018 - 2023, Boston Immigration Court

Published Oct 19, 2023

Attorney General Eric Holder appointed Judge O'Sullivan in October 2010. Judge O'Sullivan received a bachelor of arts degree in 1978 from the University of California at Los Angeles, a juris doctorate in 1981 from Antioch School of Law and a master of law degree in 1986 from Harvard University. From 1990 to October 2010, she was partner in Kaplan, O'Sullivan & Friedman in Boston, Mass. From 1986 to 1989, Judge O'Sullivan was in private practice in Boston. From 1982 to 1985, she served as director, National Immigration Project of the National Lawyers Guild, Boston. From 1981 to 1982, she was in private practice in Washington, D.C. From 1980 to 1981, Judge O'Sullivan was a staff member of the Select Commission on Immigration and Refugee Policy in Washington, D.C. She has worked intermittently as an adjunct professor at various law schools since 1987. Judge O'Sullivan is a member of the Massachusetts Bar and the State Bar of California.

Deciding Asylum Cases

Detailed data on decisions by Judge O'Sullivan were examined for the period covering fiscal years 2018 through 2023. During this period, court records show that Judge O'Sullivan decided 1267 asylum claims on their merits. Of these, she granted asylum for 1062, granted 8 other types of relief, and denied relief to 197. Converted to percentage terms, O'Sullivan denied 15.5 percent and granted 84.4 percent of asylum cases (including forms of relief other than asylum).

Figure 1 provides a comparison of Judge O'Sullivan's denial rate each fiscal year over this recent period. (Rates for years with less than 25 decisions are not shown.)

Figure 1: Percent of Asylum Matters Denied

Nationwide Comparisons

Compared to Judge O'Sullivan's denial rate of 15.5 percent, Immigration Court judges across the country denied 60.6 percent of asylum claims during this same period. Judges at the Boston Immigration Court where Judge O'Sullivan decided these cases denied asylum 49.1 percent of the time. See Figure 2.

Judge O'Sullivan's asylum grant and denial rates are compared with other judges serving on the same court in this table. Note that when an Immigration Judge serves on more than one court during the same period, separate Immigration Judge reports are created for any Court in which the judge rendered at least 100 asylum decisions.

Figure 2: Comparing Denial Rates (percents)

Why Do Denial Rates Vary Among Judges?

Although denial rates are shaped by each Judge's judicial philosophy, denial rates are also shaped by other factors, such as the types of cases on the Judge's docket, the detained status of immigrant respondents, current immigration policies, and other factors beyond an individual Judge's control. For example, TRAC has previously found that legal representation and the nationality of the asylum seeker are just two factors that appear to impact asylum decision outcomes.

The composition of cases may differ significantly between Immigration Courts in the country. Within a single Court when cases are randomly assigned to judges sitting on that Court, each Judge should have roughly a similar composition of cases given a sufficient number of asylum cases. Then variations in asylum decisions among Judges on the same Immigration Court would appear to reflect, at least in part, the judicial philosophy that the Judge brings to the bench. However, if judges within a Court are assigned to specialized dockets or hearing locations, then case compositions are likely to continue to differ and can contribute to differences in asylum denial rates.


When asylum seekers are not represented by an attorney, almost all of them (80%) are denied asylum. In contrast, a significantly higher proportion of represented asylum seekers are successful. In the case of Judge O'Sullivan, 2.1% were not represented by an attorney. See Figure 3. For the nation as a whole, about 15.7% of asylum seekers are not represented.

Figure 3: Asylum Seeker Had Representation


Asylum seekers are a diverse group. Over one hundred different nationalities had at least one hundred individuals claiming asylum decided during this period. As might be expected, immigration courts located in different parts of the country tend to have proportionately larger shares from some countries than from others. And, given the required legal grounds for a successful asylum claim, asylum seekers from some nations tend to be more successful than others.

The largest group of asylum seekers appearing before Judge O'Sullivan came from El Salvador. Individuals from this country made up 22.1% of her caseload. Other nationalities in descending order of frequency appearing before Judge O'Sullivan were: Guatemala (21.6%), Brazil (8.4%), Honduras (7.9%), Ecuador (5.1%). See Figure 4.

In the nation as a whole during this same period, major nationalities of asylum seekers, in descending order of frequency, were El Salvador (16.6%), Guatemala (15.1%), Honduras (13.8%), Mexico (9.2%), China (6.8%), India (5.1%), Venezuela (3.2%), Ecuador (3.1%), Cuba (2.4%), Nicaragua (2.3%), Brazil (2.0%), Colombia (1.4%), Cameroon (1.4%).

Figure 4: Asylum Decisions by Nationality
TRAC is a nonpartisan, nonprofit data research center affiliated with the Newhouse School of Public Communications and the Whitman School of Management, both at Syracuse University. For more information, to subscribe, or to donate, contact trac@syr.edu or call 315-443-3563.