His parents moved to Boston from Ireland a year before he was born. His father was a laborer whose gigs included digging ditches.
But McDonnell now finds himself walking a political tightrope, breaking ranks with many other Los Angeles politicians by opposing a "sanctuary state" bill that aims to prevent federal immigration agents from taking custody of people being released from California jails.
In deep blue, immigrant-rich California, it’s proven to be good politics for officials to stand up to
"I am not a Trump guy. I am not an anti-Trump guy," McDonnell said. "I am just a cop. I am about protecting public safety. I am getting hit by the Trump administration … one day and then the next day getting called anti-immigrant."
The sanctuary state bill is being pushed by Democratic leaders in Sacramento as a way of shielding people in California illegally from Trump's policies.
But McDonnell says the bill would have unintended consequences for immigrant communities. If immigration agents cannot pick up people from the jails, he said, they will go looking for those people on the streets, instilling fear among immigrants and making them less likely to cooperate with law enforcement in criminal cases.
"They are going to have no choice but to go into the communities and arrest not only the individual they are seeking but also people who are with that person, or other people in the area who are undocumented," McDonnell said. "That is something none of us want."
Other sheriffs, including Orange County Sheriff Sandra Hutchens, have voiced similar objections. The California State Sheriffs’ Assn. opposes the bill. But McDonnell is parting ways with other officials in L.A. County, where supervisors Hilda Solis and Sheila Kuehl, as well as Los Angeles Mayor
Charlie Beck, chief of the Los Angeles Police Department, where McDonnell spent most of his career before becoming Long Beach police chief and then sheriff, said Tuesday that he agrees with the bill's "underlying tenets," though he wants to make sure it does not protect criminals.
As the overseer of L.A.'s massive jail system, McDonnell is facing high stakes. Even without the sanctuary state bill, the L.A. County Sheriff's Department is at risk of losing federal funding if Trump makes good on his threat to punish law enforcement agencies that do not help with deporting immigrants in the country illegally. On Monday, the Trump administration named the L.A. County Sheriff's Department on a list of local agencies that "endanger Americans" by failing to hand over all of the jail inmates requested by immigration authorities.
For decades, law enforcement agencies in California and beyond have been wrestling with how to deal with people here illegally.
Under Special Order 40, adopted in 1979, LAPD officers may not approach people solely to inquire about immigration status.
Sheriff's deputies who patrol county streets follow a similar policy. In its jails, however, the Sheriff's Department cooperates with immigration authorities in a limited fashion.
The names and fingerprints of people booked into L.A. County jails are automatically sent to
Last year, Los Angeles County jail officials handed about 1,000 inmates to immigration agents — a small fraction of the more than 300,000 people released from the jails that year.
In California, sheriffs can comply with ICE requests, known as hold requests, to hand over only inmates who have been arrested for certain serious or violent crimes or who have prior convictions for certain crimes.
The sanctuary state bill, SB 54, which was introduced by Senate President Pro Tem Kevin de León (D-Los Angeles), would limit the information ICE receives about inmates in county jails, making it harder for immigration agents to know who is behind bars.
Under the bill, sheriffs would not be able to share databases with ICE or provide an inmate's release date.
Hold requests, which are typically used by ICE to request an inmate, allow the inmate to be held for an extra 48 hours and would be barred under the bill. Requests to notify ICE of an inmate's release date or help with an inmate's transfer would also be barred by the bill.
Sheriffs would still be able to notify federal authorities about inmates who have been convicted of certain violent felonies, but the list of crimes is narrower than currently allowed by California law. And the notification would be made to the FBI, not ICE.
"What, in effect, this would do is say we could not talk to ICE about who is in our custody, and we cannot tell them when someone is going to be released," said Hutchens, the Orange County sheriff. "Then, they get released to the street, and I am talking about violent, convicted felons."
Chris Newman, legal director for the National Day Laborer Organizing Network, said that under the bill, sheriffs will still forward inmates' fingerprints to federal authorities. He accused McDonnell of colluding with ICE to destroy the bill instead of trying to improve it.
"It is pretty unfortunate that he appears to be siding with the Trump administration in opposition to the most important human rights bill of a generation, perhaps," Newman said.
In addition to the provisions specific to county jails, the sanctuary state bill contains a general prohibition against local law enforcement agencies assisting in any type of immigration enforcement.
Claude Arnold, a retired special agent who was in charge of ICE's Los Angeles region, said that the bill, if enacted, could lead to a showdown with federal officials, who might subpoena a police agency's records or sue the agency in court.
"It forces sheriffs and police departments to harbor aliens — a federal crime," he said.
In a March 9 letter to De León explaining his opposition to the bill, McDonnell raised the specter of immigration agents casting a "wide net" in local communities after being shut out of the jails. He also wrote that the list of violent felonies where sheriffs would be permitted to notify federal authorities is too narrow, leaving out crimes including assault with a deadly weapon, shooting at an occupied dwelling and rape of an unconscious victim.
Deporting dangerous people makes immigrant communities safer, McDonnell said.
"I look at myself as a son of immigrants, and I feel somewhat sensitive about the needs of that community," he said. "But at the same time, we don't want to put predators back in the communities from where they came, to victimize people over and over again."
On Tuesday, supporters of the bill protested outside the Hall of Justice in downtown Los Angeles, where McDonnell occupies a corner office high above the city, accusing him of siding with the Trump administration and its plans to ramp up deportations.
Carrying signs and chanting in Spanish for the sheriff to listen to them, the protesters tried to enter the building and were blocked by security guards who held the doors shut.
"We are going to remember which side McDonnell was on," Pablo Alvarado, director of the National Day Laborer Organizing Network, said at a news conference on the steps. "We understand the Department of Homeland Security is bullying Sheriff McDonnell into joining its deportation force."
Times staff writer James Queally contributed to this report.