"Our hearts go out to our fellow officers and the entire community at Texas Tech".
Daniels is charged with murder.
Texas Democratic Party Deputy Executive Director Manny Garcia said in a statement Tuesday that "our words were inadequate, hurried and we apologize", adding that the tweet has been removed.
A 19-year-old student confessed to fatally shooting a Texas Tech University police officer hours after the suspect's family warned the school he could be suicidal, according to police and an arrest warrant posted online on Tuesday.
As news of the shooting was breaking late Monday, the Texas Democrats' Twitter account posted, "Allowing concealed guns on college campuses was a dumb and risky idea". The Lubbock Avalanche-Journal reported that he was a freshman from Seguin, Texas, near San Antonio.
One student left bag of sympathy cards in the middle of memorial circle asking students to write something to Officer East's family.
Officials are investigating whether the gun used to shoot East was owned by Daniels, Cpl. He rushed back into the room and found East mortally wounded and Daniels missing.
A university spokesman tells NPR that campus police were dispatched to the room of Hollis Daniels III, 19, to check on him, after his suitemates contacted the university with concerns about his welfare.
A message on the university's Twitter page sent out soon after the shooting advised people at the campus to take shelter. Abbott also said he had mobilized state law enforcement resources to aid in the investigation.
Jail records indicate Daniels had previous run-ins with the law, faced drug charges and was briefly booked into jail for speeding.
After the two responding officers allegedly found the drugs and paraphernalia, Daniels was taken to the police station for questioning.
It's unclear whether Daniels has obtained an attorney.
Police apprehended a 19-year-old student accused of fatally shooting a Texas Tech University police officer at the campus police station Monday night.
Hollis Daniels has been charged twice previously with possession of drugs or drug paraphernalia, according to the news service. Officers then brought the suspect to the police station.
The student pulled out a gun, shot an officer in the head and then fled on foot, Cook said.
- James Eppler was in the middle of class when he got the Texas Tech campus lockdown alert.
Additional information was not immediately available.