Since the Legislature has been in session, the topic of “sanctuary cities” has dominated conversation under the pink dome, mainly due to the actions of Travis County Sheriff Sally Hernandez.

Hernandez campaigned saying she would evaluate U.S. Immigration and Customs Enforcement detainer requests on a case-by-case basis and not necessarily honor every one to boost trust in minority communities. With that promise, Hernandez is not violating any law. A detainer request is just that—a request—that law-enforcement officials can choose to comply with.

Sen. Charles Perry, R-Lubbock, is looking to change the discretionary nature of these requests by making them legally binding. In Senate Bill 4, jurisdictions that do not honor detainers will face repercussions in the form of civil penalties, withdrawal of state funding and criminal charges for those in leadership roles.

In the first day of enacting her policy, Hernandez released 37 immigrants from jail. At the same time, 191 immigrants in the county were held under ICE detainer requests. Many sheriffs are claiming Travis County is the only one of Texas’ more than 200 counties to be enforcing these so-called sanctuary city policies.

In suburban areas around the state, many police departments are saying they do not question their ability to deny a detainer request.

According to law-enforcement agencies, once a person is arrested, he or she will undergo an interview. If during that interview a correctional officer has a reason to believe the arrested person is an undocumented immigrant, the officer contacts ICE.

Reasons for suspicion can include the arrestee’s origin country, if the person identifies himself or herself as being foreign-born, or fingerprinting. ICE can then choose to issue a detainer request, which gives ICE 48 hours to transfer the person into ICE custody.

Maj. Chad Norvell of the Fort Bend County Sheriff’s Office said SB 4 would not impact the way the sheriff’s office works.

“We usually have 70-80 ICE detainers in our jail at any given time,” Norvell said. “If one has a detainer placed on them, they cannot bond out for whatever offense they were arrested for.”

In 2015, ICE requested 164 detainers for undocumented immigrants in sheriff’s office custody. Of these, 61 were released directly to ICE, 22 were released to other agencies, 79 were released to the U.S. Marshals and 2 remain in custody. In 2016, 101 ICE detainers were requested, 55 undocumented immigrants were released to ICE, 16 were released to other agencies, 28 remain in custody and two had detainers withdrawn. In 2017, up to Feb. 10, 30 ICE detainers were requested, with four immigrants released directly to ICE and two released to other agencies. Twenty-three immigrants still remain in custody. One was released to the U.S. Marshals.