By Ian Swanson - 12/25/14 02:17 PM EST
Six people in New York have been arrested for threatening police since Saturday, when two officers were shot to death in their patrol car.
The latest man arrested is Tyrone Melville, 41, who allegedly called the switchboard of the Brooklyn precinct where the two slain officers were stationed.
He was charged with one felony of making terroristic threats and a misdemeanor of aggravated harassment.
Separately, another man was charged with making terroristic threats after he allegedly threatened to kill police on his Facebook page. Jose Maldonado was also arrested on Wednesday.
New York Mayor Bill De Blasio offered his thanks for the arrest on Twitter.
"Thank you to the NYPD officers who today arrested a man who threatened to kill cops, and to the good samaritan who provided key information," he tweeted.
ABC News has reported that police have received more than 40 threats since the killings of Ramos and fellow officer Wenjian Liu.
Police across the country have been on high alert since Saturday.
Vice President Biden will be in New York on Saturday to attend Ramos’s funeral.
According to Reuters, prosecutors have won convictions for threats against police officers despite the Constitution’s protections for free speech. Numerous state laws make it a crime to threaten a police officer.
This story was updated at 3:01 p.m.