A Houston-area police officer was killed yesterday — the second such tragedy in a week. The death sparked a massive dragnet for the suspect, which covered counties north and south along the Interstate 35 corridor.

The search was followed by the rare issuance of a Blue Alert, which prompts most cell phones and breaks into over-the-air programming when activated.

Nassau Bay Police Sgt. Kaila Sullivan died after being hit by a Jeep during a traffic stop Tuesday night.

Tavores Dewayne Henderson, 21, is wanted in connection to Sullivan’s death. He is described as a black man, 5 feet 7 inches tall, 130 pounds, and may be armed and dangerous. He was wanted on a domestic violence charge and fled the traffic stop, according to the Associated Press and local sources. Henderson may still have one handcuff attached to his wrist. He is pictured in the feature image of this article.

There is a reward of up to $20,000 for information leading to the suspect’s arrest deliverable to (713) 222-TIPS or the Harris County Sheriff’s Office at (713) 906-9597.

The rarely used Blue Alert took many by surprise, as it is not used as often as the Amber Alert for missing children or the Silver Alert for missing seniors.

Established by the Blue Alert Foundation, Inc., and adopted by state and local governments, the system is designed to “speed the apprehension of violent criminals who kill or seriously injure local, state, or federal law enforcement officers.”

According to the foundation’s website, 34 states have implemented the Blue Alert system. It was enacted by the National Blue Alert Act of 2013 which instructed the Department of Justice to create a national Blue Alert communication system under the direction of a national coordinator.

The Blue Alert was launched in Texas in 2008 when Gov. Rick Perry issued Executive Order RP-68. Four criteria must be met before the alert can be issued:

1.  A law enforcement officer must have been killed or seriously injured by an offender.
2. The suspected offender must be a serious risk to public safety.
3. Details such as photogrpahs, the suspect’s vehicle make and model, license plate number, etc., must be made available.
4. The agency in charge of the investigation must recommend the activation of the Blue Alert system by Texas DPS.

The maximum alert duration is 24 hours.

In Texas, in addition to the Blue, Amber, and Silver alerts, there is also the CLEAR Alert, pertaining to missing adults in immediate danger, and the Camo Alert, for current or former military members with mental illness who may isolate themselves or disappear without notice.