A Blue Alert was issued on Wednesday for a man accused of shooting an Alvarado police officer during an attack at a U.S. Immigration and Customs Enforcement detention facility on July 4, according to the Texas Department of Public Safety and the FBI.

Many Texans were awoken early Friday morning by a different kind of alarm — and the internet had some things to say.

What does a Blue Alert mean and why are they important?

A reward of up to $20,000 is being offered for information leading to the arrest of the person or persons involved in the shooting of a Harris County sheriff’s deputy.

One of two men accused in the shooting of a 29-year-old Harris County deputy overnight was taken into custody on Thursday morning, authorities said.

Update: 2:50 p.m 6/16/2021: The Blue Alert has been discontinued. Check back for more information.

DeArthur Pinson Jr., 36, is considered “armed and dangerous and should not be approached,” according to officials. Update:A man accused of shooting a DPS trooper was found deceased, according to the Mclennan County Sheriff’s Office. DeArthur Pinson Jr., 36, was located by authorities Saturday evening and he has died by suicide, Limestone County Judge Richard Duncan confirms. Trooper Chad Walker is still recovering in the hospital and is in critical condition, according to officials. Trooper Walker was taken to Baylor Scott & White - Hillcrest Hospital in Waco, where he is in critical but stable condition, officials said.